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PVL, 9.^000

Weeds

of the Prairies

Carol J. Bubar

Susan J. McGoll Linda M. Hall

Ph. D„ P. Ag.
Olds College

Ph. D„ P Ag.
University of
Saskatchewan

Ph. D., P. Ag.

Alberta Agriculture, Food
and Rural Development

Published by:

Alberta Agriculture, Food and Rural Development

Publishing Branch

7000 - 113 Street

Edmonton, Alberta

Canada T6H 5T6

Editor: Chris Kaulbars

Graphic Designer: John Gillmore

Layout and Composition: Sherrill Strauss

No part of this publication may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, electronic,
mechanical photocopying, recording or otherwise without written
permission from the Publishing Branch, Alberta Agriculture, Food and
Rural Development.

Contents

Acknowledgements

Introduction

Identifying Weeds .

Blue Flowered Species

Bluebur

Blueweed

Flax

Ground-ivy

Silky Lupine

Purple Flowered Species

Bull Thistle

Canada Thistle

Common Burdock

Creeping Bellflower

Hound’s-tongue

Nodding Thistle

Purple Loosestrife

Russian Knapweed

Spotted Knapweed 38

Tall Larkspur 40

Two-grooved Milk-vetch 42

Pink Flowered Species

American Dragonhead 46

Cow Cockle 48

Field Scabious 50

Hemp-nettle 52

Henbit 54

Pale Smartweed 56

Prickly Rose 58

Prostrate Knotweed 60

Showy Millcweed 62

Stork’s-bill 64

Water Smartweed 66

White Flowered Species

Baby’s-breath 70

Bladder Campion 72

Canada Fleabane 74

Chickweed 76

■

.. V

..1

..2

,32

,34

,36

White Flowered Species - contimied

Cleavers 78

Common Pepper-grass 80

Corn Spurry 82

Death Camas 84

Diffuse Kmapweed 86

Field Bindweed 88

Hairy Nightshade 90

Narrow-leaved Milk-vetch 92

Night-flowering Catchfly 94

Ox-eye Daisy 96

Pygmyflower 98

Round-leaved Mallow 100

Scentless Chamomile 102

Shepherd’s Purse 104

Spotted water-hemlock 106

Stinkweed 108

White Clover 110

White Cockle 112

Wild Buclcwheat 114

Wild Caraway 116

Wild Licorice 118

Wild Tomato 120

Yellow Flowered Species

Absinth 124

Argentine Canola 126

Ball Mustard 128

Black Henbane 130

Black Medick 132

Common Groundsel 134

Common Mullein 136

Dandelion 138

Dog Mustard 140

Early Yellow Locoweed 142

Flixweed 144

Goat’s-beard 146

Golden-bean 148

Gumweed 150

Leafy Spurge 152

Narrow-leaved Hawk’s-beard 154

Orange Hawkweed 156

Pasture Sage 158

Perennial Sow-thistle 160

Pineappleweed 162

Polish Canola 164

Prairie Sunflower 166

Prickly Lettuce 168

Purslane 170

Rough Cinquefoil 172

Spiny Annual Sow-thistle 174

Tall Buttercup 176

Tansy 178

Tumble Mustard 180

Wild Mustard 182

Wild Radish 184

Wood Whitlow-grass 186

Yellow Nut Sedge 188

Yellow Sweet Clover 190

Yellow Toadflax 192

Green Flowered Species

Barley 196

Barnyard Grass 198

Broad-leaved Plantain 200

Cocklebur 202

Downy Brome 204

False Ragweed 206

Field Dock 208

Field Horsetail 210

Foxtail Barley 212

Green Foxtail 214

Kochia 216

Lamb’s-quarters 218

Persian Darnel 220

Proso Millet 222

Prostrate Pigweed 224

Quack Grass 226

Redroot Pigweed 228

Russian Thistle 230

Spear-leaved Goosefoot 232

Stinging Nettle 234

Tartary Buckwheat 236

Thyme-leaved Spurge 238

Wheat 240

Wild Oats 242

Index 251

Organized by Common Name 251

Organized by Scientific Name 259

Organized by Family Name 263

Digitized by the Internet Archive
in 2016

https://archive.org/details/weedsofprairiesOObuba

1 his book is the work of many photographers, weed scientists and agricultural
experts. Written descriptions in the book have been compiled from the
observations and research of many botanists and weed scientists. The authors
would like to specifically acknowledge a number of individuals.

Acknowledgements

Photographers:

• Valerie Sowiak, AAFRD, Edmonton, Alberta

• Beth Hoar, AAFRD, Edmonton, Alberta

• Linda Hall, AAFRD, Edmonton, Alberta

• Sue McColl, University of Saskatchewan, Saskatoon, Saskatchewan

• Carol Bubar, Olds College, Olds, Alberta

• Susan Weaver, AAFC, Harrow, Ontario

• Doug Derksen, AAFC, Brandon, Manitoba

• Rick Holm, University of Saskatchewan, Saskatoon, Saskatchewan

• Bill Vanden Born, University of Alberta, Edmonton, Alberta

• Ian Morrison, University of Alberta, Edmonton, Alberta

• France Royer, Edmonton, Alberta

• Richard Dickinson, Toronto, Ontario
All have made contributions to the book.

Information on the typical location of weeds was contributed by:

• Dan Cole, AAFRD, Edmonton, Alberta

• Kelly Cooley, MD Fincher Creek, Fincher Creek, Alberta

• Doug Derksen, AAFC, Brandon, Manitoba

• Gary Martin, University of Manitoba, Winnipeg, Manitoba

• John Huffman, AAFRD, Grand Frairie, Alberta

• Vern Harms, University of Saskatchewan, Saskatoon, Saskatchewan

• Feter Regitinig, Roger’s Sugar, Taber, Alberta

Weed distribution maps were produced with the able assistance of Stephen Bowkett, Land Resources Unit,
Semiarid Frairie Agricultural Research Centre, Swift Current, Saskatchewan and Gordon Thomas,
Saskatoon, Saskatchewan - both with Agriculture and Agri-Food Canada.

Introduction

Weeds of the Prairies was developed as a practical field guide for
those who need a relatively non-technical aid to identify common
weeds across the Canadian prairie provinces.

This book does not contain all the weeds, nor all the native plants
that can be found on the prairies. However, it does include over
100 weeds that can be found in agricultural fields, pastures,
rangeland, waste areas, gardens and roadsides.

The primary classification of weeds in this book is by flower color, which match the colors seen
on the outside of the pages. Within each color group, species are alphabetized by the common
name of the weed. Maps showing the per cent of fields where the weed is found are presented
for many of the weed species in this book.

Each weed discussed has charts on life cycle and habitat. The life cycle chart describes whether
the weed will grow as an annual, biennial and so on. The habitat charts show how likely the
weed is to be found growing in certain areas. The relative frequency appears in the number of
brush strokes beside the area description. Three strokes beside the term “conventional tillage”
means the weed occurs fairly frequently in these areas. The range of brush strokes goes from
zero - meaning not a habitat for this weed - to three - meaning a very common habitat.

At the end of the book, there is a complete species list that includes both the common and
Latin names of the weed. In addition, we have provided an alphabetized plant family listing
with the weeds of each family also alphabetized.

All attempts have been made to gather representative photographs of these weeds at several
stages of growth. Where appropriate and available, photographs of infestations, key features
and/or similar species are also presented. Descriptions and names were compiled carefully, but
in any project of this size, errors can occur.

If you notice any errors or have information or photographs to add, please contact L.M. Hall,
Alberta Agriculture, Food and Rural Development, 6903 - 116 Street, Edmonton, AB,

T6H 4P2.

Identifying weeds

Identifying a weed can sometimes be a challenge. Knowing what the parts of the weed are called and
being able to describe them can certainly help in identification. Here are some drawings of basic weed
types: broadleaf weeds and grass weeds. In addition, a number of images here will show leaf types, leaf
arrangements and so on to help with identification.

Broadleaf seedling

Broadleaf stem and leaf

Leaf attachment

leaf with petiole sessile

Leaf arrangement

alternate basal opposite whorled

Leaf type

simple palmate compound simple pinnate compound trifoliolate

palmate pinnate

Stipules at stem node

stipules

Leaf shapes

spoon-shaped/

spatulate

Stem with ocrea

ocrea

Growth habit

erect twining

Rhizome and stolon

rhizome stolon

Broadleaf flower structure

Inflorescence types

flower cluster in involucral bracts
leaf axil

aster family - ray
flower

raceme

aster family - disk
flower

spike

simple umbel

aster family - ray
and disk flower

compound umbel

Grass collar

Grass spikelet with two florets

Blue

Flowered Species

Bluebur

Lappula squarrosa

Other names

Hitch-hiker, stickseed, sticlcweed

Family

Borage Boraginaceae

Seedling

Cotyledons are oval with short petioles.

They are covered with short hair and have a
small “bump” at the tip. The first true leaves
emerge one at a time and appear folded in half.

They are narrowly ovate, densely hairy and have a
distinct crease down the middle. Some people claim that the
seedlings smell like a mouse-infested building. This seedling may be confused
with night-flowering catchfly. Catchfly seedlings have a rounder cotyledon tip and true
leaves that emerge in pairs. They also lack the crease and odor associated with bluebur
seedlings.

Juvenile

Bluebur forms a low-growing rosette of leaves that are more spatulate than in the seedling,
but that are also densely hairy and creased in appearance. Stems are erect, hairy and often
much-branched. The leaves become reduced in size as they near the top of the plant.

Mature

Tiny, blue flowers are located in racemes with small bracts resembling leaves below each
flower. The flowers are similar to those of the popular garden perennial “forget-me-not.”
Each flower produces four bur-like seeds with two rows of sharp, hooked prickles. The
prickly seeds readily stick to clothing and animal hair.

Key features

Densely hairy, creased leaves; tiny blue flowers; prickly, bur-like seeds

Seedlini

Blueweed

Echium vulgare

Other names

Viper’s bugloss, blue devil

Family

Borage Boraginaceae

Seedling

Cotyledons are oval and covered with fine hairs. The first true leaf is densely hairy and more
elongated than the cotyledons. The leaf has a creased appearance.

Juvenile

Blueweed forms a large, black tap root and a basal rosette in the first year. The basal leaves
are stalked, narrowly elongated and covered with stiff, spreading hairs. Stems are upright,
and there may be one to several stems per tap root. The stem leaves are sessile and smaller
than the rosette leaves. Both the stems and upper leaves are covered with a mixture of short
and long stiff hairs. The longer hairs often have conspicuous swollen bases that make the
stem appear speckled. Blueweed plants may cause rashes in sensitive individuals, so plants
should be handled with care.

Mature

Flowers are typically reddish-purple in bud and turn bright blue after emergence. They are
funnel-shaped with protruding stamens and are located in clusters in the axils of upper
leaves. Each flower produces four angular, rough, grey to brown seeds.

Key features

Large tap root; dense, stiff hairs with swollen bases; bright blue flowers in clusters

Life Cycle

annual winter annual biennial creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Flax

Limm usitatissimum

Family

Flax Linaceae

Seedling

Cotyledons are oval and slightly fleshy. They are larger than the true leaves, which are
linear with pointy tips. The small, sessile leaves are alternate, but the first two may
appear opposite.

Juvenile

Flax has a branched tap root and erect growth. There is usually one main stem and
irregular, multi-branching at the top of the plant. Small, sessile leaves spiral alternately
around the stem. Volunteer flax can be difficult to control in both cereals and broadleaf
crops. Since it may remain green longer than the crop, it can interfere with harvesting and
subsequent grain storage.

Mature

Flowers form at the ends of the upper branches and though usually blue, they can also be
white or pale pink. Each flower opens for one day only. There are five petals, five sepals, five
stamens and the developing fruit has five main segments, each divided by a partition. Full
seed set is ten seeds per “boll” or capsule. The bolls change from green to brown as they
ripen and hold mature seed for a long time without shattering. Mature seeds are oval, light
brown (occasionally yellow) and very glossy due to a surface mucilage that causes the seed
to feel sticky when wet.

Key features

Small, pointed, linear leaves alternately spiralled around the stem; blue flowers opening for
one day only; mature “bolls” releasing seeds when machine-harvested

Seedlini

Juvenile

Ground-ivy

Glechoma hederacea

Other names

Creeping Charlie, gill-over-the-ground

Family

Mint Lamiaceae

Seedling

Seedlings are not commonly seen.

Juvenile

Stems are prostrate and square in cross-section. Propagation is largely by these creeping
stems that root at the nodes. Ground-ivy can be very aggressive in turf, particularly in shady
areas. Leaves are opposite with long petioles. The round to heart-shaped leaves have
palmate venation and regularly-scalloped margins. Ground-ivy has an unpleasant, sour,
minty odor. The prostrate growth and long petioles of ground-ivy distinguish it from henbit,
a mint family weed with an erect growth habit and sessile upper leaves.

Mature

Short, flowering branches are produced from leaf axils of the prostrate stems. These
branches are partially to fully erect. Small clusters of purple-blue flowers are in the leaf
axils. Each flower is a small, two-lipped tube. Four tiny brown seeds are contained in a
persistent calyx.

Key features

Square, prostrate stems that root at the nodes; opposite, petioled leaves with scalloped leaf
margins; small, purple flowers produced in leaf axils of erect, flowering stems

annual

winter annual

Life Cycle

biennial creeping perennial simple perennial

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf ^

waste areas 0

Juvenile ! prostrate, creeping growth habit

Silky Lupine

Lupinus sericeus

Family

Pea Fabaceae

Seedling

Seedlings are not commonly seen in their rangeland habitat.

Juvenile

Silky lupine is a tap-rooted legume with an erect stem covered in dense, silky hairs. The
alternate leaves are compound palmate with dense, silky hairs covering the leaflets. The
closely related species, silvery lupine, has leaflets that are sparsely hairy on the upper
surface, though densely silvery-haired underneath.

Mature

Although a meadow of blooming lupines is a delight to hikers, both silky lupine and silvery
lupine are poisonous to livestock. Silky lupine racemes have dense blue to bluish-purple
flowers. The flower can also be blue and white bi-colored. Silvery lupine, on the other hand,
has pale violet to almost white flowers arranged in less dense racemes. The large “standard”
petal of a silky lupine flower is densely hairy on the back, while the standard petal of silvery
lupine is hairless or nearly so. Pods are flattened and contain several seeds that are
especially poisonous.

Key features

Compound palmate leaves covered on both sides with dense, silky hairs; deep blue, pea-type
flowers in dense racemes; dense, silky hairs on the back of the “standard” petal

Similar species

Silvery lupine Lupinus argenteus

Juvenile

Flower deep blue and pea-like

Mature

Purple

Flowered Species

Bull Thistle

Cirsium vulgare

Family

Sunflower Asteraceae

Cotyledons are oval and lacking petioles. The first true leaf is oval to oblong with a fringe of
spines. The second true leaf has dense, white hairs on the upper surface, which is an easy
way to distinguish this weed from Canada thistle at the seedling stage.

Juvenile

Bull thistle forms a deep tap root and a large, flat, basal rosette in the first year. Rosette
leaves are deeply lobed, and the lobes occur in clusters of two to three. Each lobe has long
sharp spines on the margins and at the tip. Unlike other thistles, the upper leaf surface is
prickly while the underside is covered with fine, wooly hair. Stems are erect, tall and often
widely-branched. The stem surface is hairy and may have narrow, spiny, leaf-like “wings” on
the middle and upper portions. The leaves on the upper stems become smaller toward the
top of the plant.

Mature

Large, flask-shaped heads are found at the tops of branches. Each head has long, purple
disk flowers enclosed by narrow, overlapping bracts tipped with a yellowish spine. The head
size and long sharp spines on the involucral bracts help to separate this species from
Canada thistle. The flowers produce a single, greyish-brown seed with dark lines on the
surface. The seeds resemble those of Canada thistle except that they are larger and have a
longer, more-branched pappus.

Key features

Large, flat, basal rosette in first year; leaves with lobes in clusters and a prickly surface;
large, flask-shaped heads with long sharp spines on bract tips

Juvenile

Mature

Canada Thistle

Cirsium arvense

Other names

Creeping thistle

Family

Sunflower Asteraceae

Seedling

Seedlings have oblong to broadly oval,
somewhat fleshy cotyledons. Shoots that
emerge from underground root buds lack
cotyledons. Both types have ovate first true
leaves with sharp spines along the margins.

Juvenile

Canada thistle has deep, horizontal, creeping roots and often forms
dense patches. It is largely the spreading underground roots that make control of this weed
so difficult. The rosette leaves are usually smooth and irregularly-lobed with a spiny-toothed
margin. However, plants vary in the extent of lobing, the length of spines on the margin and
in the presence or absence of hair on the undersides of the leaves. Stems are erect, hollow
and have many alternate, sessile leaves. The stem surface is usually smooth although spines
may be present near the base of the plant.

Mature

Heads are numerous in clusters and are smaller than other thistle species. The disk flowers
are pink-purple, occasionally white, and surrounded by narrow, flattened involucral bracts
ending in short, weak prickles. Bull thistle is sometimes confused with Canada thistle. Its
heads are much larger than Canada thistle, and the bracts are more slender and spine-
tipped. In addition, the leaves of bull thistle have short prickles all over the surface. Canada
thistle has male and female flowers in heads located on separate plants. The male heads are
globe-shaped in contrast to the more flask-shaped female heads. Each female flower is
capable of producing a single, tan-colored, slightly curved seed. The seeds have a feathery
pappus and are readily dispersed by wind.

% of fields
where found

■i

5-15

■i

16-50

50-1-

not

surveyed

Key features

Deep, creeping roots; irregularly-lobed leaves with spines on margins only; small male and
female heads on separate plants

Mature

Common Burdock

Arctium minus

Family

Sunflower Asteraceae

Seedling

Cotyledons are oval and have noticeable veins. The first true leaves are petioled and ovate
with entire to slightly wavy margins. The surface of the leaves is somewhat hairy and
wrinkled.

Juvenile

Common burdock develops a thick, fleshy tap root and large basal rosette in the first year.
The rosette leaves are ovate to triangular with a heart-shaped base and a wavy margin.
Common burdock leaves are often very large and resemble rhubarb except that the
undersides are wooly-hairy and the petioles are hollow. Stems are erect and often much-
branched. They are rough-hairy, hollow and grooved lengthwise. Stem leaves are usually
much smaller and less heart-shaped than the rosette leaves.

Mature

Heads are almost round and are found either singly or in clusters at the ends of branches.
Each head has purple disk flowers surrounded by a receptacle with involucral bracts
modified into narrow, hooked bristles. This structure forms the bur that aids in the dispersal
of common burdock seeds by animals and man. The seeds found within the bur are oblong,
smooth and mottled. They look somewhat like narrow, curved sunflower seeds.

Key features

Thick, fleshy tap root; large, heart-shaped basal leaves; receptacle with narrow, hooked
bristles forming a bur

Life Cycle

annual winter annual biennial creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation ^

roadsides

forage crops, hay fields ^

turf

waste areas

Juvenile: lai'ge basal ivsette

Mature

Creeping Bellflower

Campanula rapunculoides

Other names

Garden bluebell

Family

Bluebell Campanulaceae

Seedling

Cotyledons are oval. First true leaves are broadly ovate to heart-shaped. Both the leaf blades
and petioles are hairy.

Juvenile

Creeping bellflower escapes from gardens and tends to choke out flower beds and creep into
lawns. In addition to propagation by seed, it has persistent, fleshy rhizomes and storage
tubers, making this an extremely difficult weed to eradicate. Young plants growing from the
rhizomes are stemless. The leaves are heart-shaped with fine, irregular toothing and long
petioles. Plants with stems are also produced. Stems are tall and erect with alternate leaves
that become progressively smaller toward the top of the plant. Also, stem leaves become less
heart-shaped and have shorter petioles toward the top of the plant.

Mature

The flowers are violet, five-pointed bells in long, leafy racemes at the tops of stems. The
leaves of the raceme are smaller, narrower and sessile. This plant is quite attractive in
bloom, and people tend to overlook its weedy nature at first. Each flower develops into a
many-seeded, spherical capsule that opens with tiny pores. Seeds are light brown and shiny.

Key leatures

An urban weed with extensive, fleshy rhizomes and tubers; stemless young plants growing
from rhizomes; attractive racemes of violet, bell-shaped flowers

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Flower: bell-shaped flowers in raceme

Mature

Hound’s-tongue

Cynoglossum officinale

Family

Borage Boraginaceae

Seedling

Cotyledons are oval with short stalks united at the base. The surface of each cotyledon is
covered with short, stiff hairs directed toward the tip. The first true leaves are also hairy,
especially on the undersurface. They have oval blades and elongated petioles.

Juvenile

Hound’s-tongue produces a thick, deep tap root and basal rosette in the first year. The
rosette leaves are petioled, broad and oblong, closely resembling the size and shape of a
dog’s tongue. They are also soft and velvety to the touch. In the second year, stems are
formed that often branch near the top of the plant. The stem leaves are stalkless, narrower
and more pointed than the basal leaves. The entire plant is covered with soft white hairs.

Mature

The reddish-purple or maroon flowers are located in racemes emerging from upper leaf
axils. Each flower has five sepals joined together at the base to form a star. The petals are
also fused into a funnel or cup shape. The flowers produce four triangular but rounded
seeds with a flattened upper surface. The seeds are covered with short, barbed prickles that
enable them to be easily attached to and spread by animals.

Key features

Broad basal leaves in the shape of a dog’s tongue; soft white hairs over the entire plant;
reddish-purple cup-shaped flowers in a raceme

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields ^

turf

waste areas

Mature

Juvenile

Nodding Thistle

Carduus nutans

Other names

Musk thistle

Family

Sunflower Asteraceae

Seedling

Cotyledons are oblong. The true leaves have irregularly lobed margins with spiny-tipped
teeth. The leaves are light greyish-green and may be sparsely hairy.

Juvenile

Nodding thistle has a long, fleshy tap root and forms a large, flat rosette in the first year.
The rosette leaves have deeply lobed, spiny margins. Stems elongate in the second year.
They are usually sparsely branched and covered with winged prickles. Stem leaves are
alternate and deeply lobed with spiny margins.

Mature

Large, showy flower heads are solitary at the ends of branches. Unlike the rest of the plant,
the stems are naked just below the flower heads. The disk flowers of the head are bright
purple. Bracts around each flower head are in loose whorls with strong sharp spines at the
tip. The outer bracts are bent baclcwards, and most of the heads tend to nod. The seeds are
shiny yellow-brown with a white pappus of long, unbranched hairs. The spread of nodding
thistle has been somewhat limited by the introduction of an insect (Rhinocyllus conicus -
a flower weevil) that feeds on the developing seeds.

Key features

Winged prickles along stem except below flower heads; large, nodding, purple flower heads;
involucral bracts spine-tipped and bent backwards

Purple Loosestrife

Lythrum salicaria

Family

Loosestrife Lythraceae

Seedling

Seedlings are not commonly seen. Purple loosestrife forms large colonies in wetlands,
marshy areas, ditches and roadsides. It is a major weed in eastern Canada, and infestations
are becoming more frequent on the prairies.

Juvenile

In addition to a fibrous root system, purple loosestrife has thick, fleshy roots that can
produce new, above-ground shoots. Established plants have a large crown that produces
new buds each year. Although propagation is mainly from seed, stem pieces that have
broken off or been mowed can also produce roots. Purple loosestrife has tall, branched,
erect stems that are usually square in cross-section. Sessile leaves occur in twos or threes
at the stem nodes. They are lanceolate in shape with entire margins. Larger leaves may
have rounded lobes at the base. Fireweed is sometimes mistaken. for purple loosestrife.

The leaves of fireweed have short petioles and distinctive lateral veins that run parallel
to the margins.

Mature

Bright magenta flowers are produced in long, dense, leafy spikes. The leaves in the
inflorescence are alternate and smaller than lower leaves. Fireweed has less dense, non-
leafy racemes. Individual flowers of purple loosestrife have five to seven petals and sepals
that are united below the petals, while fireweed flowers have four petals. The seed capsule
of purple loosestrife contains many tiny reddish-brown seeds. To say it is a prolific seed
producer is an understatement. In one year, one plant may produce over two million seeds!
The capsule is long and narrow containing seeds with tufts of silky hairs at the tips.

Key features

Leaves in twos or threes at stem nodes; square stems; showy, magenta flowers in long,
dense, leafy spikes

Similar species

Fireweed Epilobium angustifolium

Juvenile

Mature! with dense, leafy spikes

Infestation

Similar species: Fireweed

Russian Knapweed

Centaurea repens

Family

Sunflower Asteraceae

Seedling

Cotyledons are oval. True leaves are hairy, greyish-green with shallow, irregularly-lobed
margins. It is more commonly seen growing from the rootstock than as a seedling. Russian
knapweed was introduced with alfalfa seed.

Juvenile

Russian knapweed has black to dark brown, scaly roots that penetrate the soil deeply and
are widely spreading. Buds on the roots develop into leafy shoots and dense patches of this
weed are a problem to control in rangeland and occasionally in field crops. The stems are
much-branched and covered with matted, soft grey hairs to give a grey-green appearance.
Lower leaves are alternate, sessile to clasping, shallowly and irregularly lobed or toothed.
The upper leaves are smaller, usually entire and often end in a soft spine. Young leaves are
grey-green and wooly, older leaves less so.

Mature

Spherical, flower heads are produced at the ends of upper, leafy branches. They appear
silvery before opening. The receptacle holds only disk-type flowers that are purple to
pinkish, becoming straw-colored with age. The whorled involucral bracts are shingle-like
with entire margins. They are greenish at the base but papery and white at the tip. Seeds
are hairless, white, oval and flattened. The pappus is composed of stiff white bristles, which
soon fall off.

Key features

Black, scaly roots that extend deep and wide; papery bracts around heads; young leaves
grey-green and wooly-hairy

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Knapweed

Family

Sunflower Asteraceae

Spotted

Centaurea maculosa

Seedling

Cotyledons are oval with short stalks. The first true leaves are spoon-shaped with entire to
wavy-edged margins.

Juvenile

Spotted knapweed forms a large tap root and rosette of leaves that are deeply divided into
narrow segments. The leaves of its close relative, diffuse knapweed, are much more finely
divided by comparison. In both species, the early leaves are covered with a thin layer of
matted, wooly hair resembling a cobweb. Spotted knapweed produces erect, hairy stems
that are typically less branched than diffuse knapweed. The upper stem leaves are almost
linear. Both knapweeds contain a bitter-tasting chemical that makes them highly
unpalatable, although not poisonous. They have taken over vast areas of rangeland in the
interior of British Columbia and have greatly reduced the availability of desired forage.

Mature

Ovate heads are produced in clusters at the top of the plant. The tiny flowers are pink to
purple, rarely white. From a distance, spotted knapweed looks a little like Canada thistle.
The flowers are surrounded by oval bracts with a black-tipped fringe resembling a false
eyelash. The involucral bracts of diffuse knapweed, on the other hand, are triangular and
spine-tipped. Another knapweed species, yellow star-thistle, has bracts that are modified
into narrow, sharp spines. Spotted knapweed seeds are narrowly oval, brown and have a
“crown” of stiff bristles.

Key features

Deeply lobed, “cobwebby” basal leaves; generally purple flowers; oval bracts with a black-
tipped fringe

Similar species

Yellow star-thistle Centaurea solstitialis

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland 0^^/^

wetland

reduced tillage

irrigation

roadsides <

forage crops, hay fields

turf

waste areas

Flower: heads with black f ringed bracts

Mature

Infestation

Tall Larkspur

Delphinium glaucum

Family

Buttercup Ranunculaceae

Seedling

Cotyledons are ovate and long-stalked. The true leaves have long petioles and a broad blade
with three to five rounded lobes.

Juvenile

Tall larkspur produces tall, erect, usually hollow stems from a large, woody tap root. The
stems are often covered with a bluish waxy coating or “bloom.” The leaves are palmately
divided into five primary lobes, which are in turn subdivided into narrow segments. They
resemble a hand with the fingers stretched outwards. The leaves are usually smooth, but
may be somewhat hairy on the margins and undersides. Although a highly attractive plant,
tall larkspur is very poisonous, especially to cattle. Poisonings usually occur in early spring
when the young plants are most toxic and before better forage is available.

Mature

The deep blue or purplish flowers are found on long racemes. Individual flowers are highly
irregular with a pronounced downward-pointing spur. Each flower produces three pods that
open to release irregularly-shaped brownish-purple seeds. The related species, low larkspur,
is not only a much smaller plant than tall larkspur, but it has two-toned flowers that are
white and bluish-purple.

Key features

Stems with bluish waxy bloom; palmately divided leaves; irregular, blue-purple flowers with
a downward-pointing spur

Similar species

Low larkspur Delphinium bicolor

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas ^

Mature

Two -grooved Milk-vetch

Astragalus bisulcatus

Family

Pea Fabaceae

Seedling

Cotyledons are oval and the first true leaves are trifoliolate and long-stalked. Leaves
produced later are pinnately compound.

Juvenile

Two-grooved milk-vetch forms deep, tap rooted plants that have several stems emerging
from a woody, branched crown. Individual stems are coarse, tough and sparsely covered
with bristly white hair. Leaves are pinnately compound with 17 to 27 narrowly oval leaflets.
Each leaflet is white and hairy on the underside, but smooth or only sparingly hairy on the
top. Normally a palatable plant, two-grooved milk-vetch can become poisonous when
growing in dry, alkaline soils. In those situations, it may take up and concentrate high
amounts of the mineral selenium in its tissues.

Mature

Dense, spike-like racemes are found on thick stalks at the top of the plant. The reddish-
purple, pea-like flowers are often reflexed or downward-pointing. Each flower produces
linear pods that are similarly reflexed. The common name for this weed comes from the
characteristic two deep grooves found on the upper side of the pod. The pods open to
release tiny, oval, reddish-brown to green seeds that have a notch on one side.

Key features

Pinnately compound leaves with 17 to 27 leaflets having hairy white undersides; dense,
spike-like racemes of reddish-purple flowers; linear pods with two deep grooves on the
upper side

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields ^

turf

waste areas

Mature

Pink

Flowered Species

Family

Mint Lamiaceae

Seedling

The round cotyledons of American
dragonhead have prominent, rounded basal
lobes. The true leaves are opposite and oval
shaped with scalloped margins. American
dragonhead may be confused with henbit, which has
similar seedling leaves. The rounded basal lobes of American
dragonhead cotyledons are useful to distinguish it from henbit seedlings, which
have pointed basal lobes on the cotyledons.

American Dragonhead

Dracocephalum parviflorum

Juvenile

Stems are erect and square in cross-section with sparse hair. The leaves are opposite and
petioled. Juvenile and mature leaves of American dragonhead are lanceolate and coarsely-
toothed and are distinctly different from seedling leaves. The teeth often narrow into a spiny
tip.

Mature

Small flowers are produced in dense spikes at the ends of branches. Flower color varies
from almost white to pale pink or purple. The flower spikes of American dragonhead are
soft to the touch, unlike hemp-nettle flowers that are very spiny. Each small flower produces
four black seeds that are ridged and angled on one side and rounded on the other.

% of fields
where found
0

50 +
not

surveyed

Key features

Scalloped margins of seedling leaves; square stem and opposite leaves with spiny-toothed
margins on the adult; soft dense flower spikes

Juvenile

Flower

Cow Cockle

Vaccaria pyramidata

Other names

Soapwort

Family

Pink Caryophyllaceae

Seedling

Cow coclde has narrow, elongated, smooth
cotyledons with short stalks. The first true
leaves emerge in a pair. They look very similar
to the cotyledons except the true leaves have a
distinct crease down the center.

Juvenile

Stems are upright, much-branched and have prominent, swollen nodes. Leaves are
opposite, sessile and joined at the base. They are oblong with pointed tips and entire
margins. Both the stems and leaves are smooth and covered with a bluish-white waxy
coating or “bloom.” The leaves are thick and feel almost leathery to the touch.

Mature

Flowers are loosely grouped at the ends of the stems. Each flower has five notched, deep
pink petals. The petals are surrounded by a green, flask-shaped calyx with five light green
ribs. Fruits are brown, elongated capsules opening with four teeth. Each capsule contains
many spherical black seeds with a bumpy surface. The seeds are a common contaminant
of feed grain and are poisonous to livestock.

% of fields
where found
0

MB 16-50
50-1-

‘g not
surveyed

Key features

Opposite, smooth leaves; bluish-white waxy bloom; green, five-ribbed calyx

Mature

Flower

Key five-ribbed calyx

Field Scabious

Knautia arvensis

Other names

Blue buttons

Family

Teasel Dipsacaceae

Seedling

Cotyledons are oval and notched at the tip. The first true leaves are petioled and oval to
oblong in shape.

Juvenile

Field scabious initially forms a deep tap root and a large, basal rosette. The rosette leaves
are broadest in the middle and tapered at both ends. They frequently have a coarsely-
toothed margin. Sturdy, erect stems are produced that branch sparingly at the top of the
plant. The upper leaves are oppositely arranged and sessile. They are deeply and pinnately
lobed into narrow, finger-like segments. The entire plant is covered with short, stiff hairs.

Mature

Small flowers are located in dense heads at the ends of long branches. The flowers may vary
from pink to pale purple or even blue. Although it is tempting to place this weed in the
Asteraceae, it does not belong to that family. Each tiny, funnel-shaped flower in the head
produces a single, hairy, rectangular seed.

Key features

Upper leaves pinnately lobed and opposite; entire plant covered with short, stiff hairs; pink
to blue flowers in dense heads

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

FIOWGr! head of dense flowers

Juvenile

Mature

Hemp-nettle

Gakopsis tetrahit

Family

Mint Lamiaceae

Seedling

The cotyledons of hemp-nettle have
distinctly pointed basal lobes, long stalks
and are slightly indented at the tip. True
leaves are opposite, hairy and have
coarsely-toothed margins. Seedlings of
yellow-flowered hemp-nettle are
indistinguishable from hemp-nettle.

Juvenile

The stem of hemp-nettle is square in cross section and covered with downward-
pointing, bristly hairs. Although these hairs can penetrate the skin and cause irritation,
they do not produce the extreme reaction caused by the specialized hairs of stinging nettle.
Hemp-nettle also lacks rhizomes and stipules at the nodes, which are characteristic of
stinging nettle. Hemp-nettle stems are conspicuously swollen below the nodes. The
oppositely arranged leaves are elliptical with long petioles and are covered with stiff hairs.

Mature

Flowers are produced in clusters in the upper leaf axils. Each flower is a pink, two-lipped
tube, although color can vary from white to purple to variegated. The five-pointed calyx
surrounding each flower is extremely spiny, making hemp-nettle very unpleasant to touch
at this stage. The four seeds produced by each flower remain inside the persistent calyx
until they disperse at maturity. Seeds are shaped like a teardrop and have a grey, brown
and black mottled surface. There is a round scar at the base of the seed. The mature plant
of yellow-flowered hemp-nettle can be distinguished from hemp-nettle by its larger size and
pale yellow flowers.

% of fields
where found
0

5-15
16-50

50-1-
not

surveyed

Key features

Stems swollen below the nodes; bristly, downward-pointing hairs covering the square stem;
opposite leaves with long petioles

Similar species

Yellow-flowered hemp-nettle Galeopsis speciosa

Life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

Henbit

Lamium amplexicaule

Family

Mint Lamiaceae

Seedling

Cotyledons of henbit are round and slightly indented at the top. Basal lobes of the
cotyledons are pointed. The true leaves are opposite with scalloped margins and are similar
to the first true leaves of American dragonhead. However, the cotyledons of American
dragonhead have rounded basal lobes.

Juvenile

Stems of henbit are square in cross section and weakly erect. Branching occurs near the
base of the plant. Leaves are oppositely arranged and have irregular, round-toothed margins.
The lower leaves of henbit are long-stalked while upper leaves are sessile and clasp the
stem. The erect stems and clasping upper leaves distinguish henbit from ground-ivy, which
is mostly prostrate with long-stalked leaves.

Mature

Pink to purplish flowers are clustered in the axils of upper clasping leaves. Each small
flower is a two-lipped tube. The upper lip is unlobed and has a tuft of hair on the top.

The lower lip is two-lobed. Each flower produces four brown seeds with white dots.

Key features

Square, weakly erect stems; long-petioled lower leaves and clasping upper leaves; opposite
leaves with irregular, round-toothed margins

Pale Smartweed

Polygonum lapathifolium

Family

Buclovheat Polygonaceae

Seedling

Cotyledons are narrowly elliptical and
joined at the base. True leaves emerge
one at a time. They are lanceolate with
short petioles and entire margins.

Juvenile

Stems are branched and vary from erect to
partially prostrate in growth habit. They are
slightly swollen above the nodes. The ocrea at each
node is smooth and papery. The upper margin is either
entire or has short hairs. The ocrea is key to differentiating both pale
smartweed and green smartweed from lady’s-thumb. Lady’s-thumb has short hairs on the
surface of the ocrea and a fringe of visible hair on the upper margin of the ocrea. Pale and
green smartweed leaves may or may not have a purplish blotch on the upper surface. The
blotch is usually present on lady’s-thumb leaves. The first five to seven leaves of pale
smartweed and green smartweed have white matted hair on the undersurface. Subsequent
leaves have tiny, yellow glands dotted on the undersurface. Both these features are lacking
on lady’s-thumb leaves.

Mature

Flowers lack petals but sepals are often colored. Pale smartweed flowers are pinkish-white
or greenish-white in dense, elongated spikes. Green smartweed has greenish-white flowers
in erect spikes, which are shorter and plumper than those of pale smartweed. Lady’s-thumb
has pink-flowered spikes. Both pale smartweed and green smartweed have tiny, yellowish
glands on the upper stems below the spikes. These glands are absent on upper stems of
lady’s-thumb. Seeds of pale and green smartweed are black, shiny and rounded with a
pointy tip. The flattened sides are dented or hollow in the middle. Lady’s-thumb seeds are
three-sided or flattened, but not dented on the flattened sides.

Key features

Smooth, papery ocreas at swollen stem nodes; leaf undersurface with white matted hair or
tiny, dotted glands; tiny glands on upper stems below spikes

Similar species

Green smartweed Polygonum scabrum\ lady’s-thumb Polygonum persicaria

% of fields
where found
0

Wm 5-15
EH 16-50

1, Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

Prickly Rose

Rosa acicularis

Other names

Wild rose

Family

Rose Rosaceae

Seedling

Seedlings are not commonly seen.

Juvenile

Three species of wild shrubby roses readily
hybridize, making identification difficult. Prairie rose,

Rosa arkansana, is a short, low shrub with few branches. Its
stems mostly die back each year. It is easier to confuse prickly rose and Woods’
rose, Rosa woodsii, which are much taller shrubs, multi-branched and have persistent stems
from year to year. Pricldy rose is a bushy shrub of pastures. It has erect, stout stems densely
covered with thorns. Stems of Woods’ rose have thorns that are scattered or only near the
base. The compound pinnate leaves of both species are alternate with toothed leaflets.
Leaves of prickly rose have three to seven leaflets, commonly five. Woods’ rose normally has
either five to seven or seven to nine leaflets. Prickles are absent below the stipules in prickly
rose but are present in Woods’ rose. Stipules of prickly rose are hairy and densely glandular
while stipules of Woods’ rose are sparsely so.

Mature

Flowers are pink, five petalled and usually solitary. The ovary and sepals of each flower
develop into the fleshy fruit or “rosehip,” which contains many seeds. The rosehip is round
to pear-shaped with a distinct stalk or “neck” below. Woods’ rose fruits are spherical but
lack a neck.

% of fields
where found

Key features

Thorny stems; pinnately compound leaves, commonly with five leaflets; rosehips on distinct
necks

Similar species

Prairie rose Rosa arkansana, Woods’ rose Rosa woodsii

Life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

Mature

Juvenile

Flower

Prostrate Knotweed

Polygonum aviculare

Other names

Kjiotweed, knotgrass, doorweed

Family

Buclovheat Polygonaceae

Seedling

Cotyledons are narrow and united at the
base. The first true leaves are narrowly oval
with short stalks.

Juvenile

As its name suggests, prostrate knotweed frequently
spreads its stems flat over the ground in open areas.

However, when the weed grows in more densely populated sites, its
stems may be partly or even fully erect. The thin, wiry stems have prominent, swollen
nodes, giving them the appearance of a piece of string with knots tied in it. The silvery
colored ocreas serve to further emphasize the swollen nodes. Stems are typically much-
branched with small, alternate leaves that are broadest in the middle and narrow at both
ends. The entire plant often has a bluish-green color. There are several closely related and
very similar looking knotweed species. Striate knotweed, also found in Western Canada,
may be distinguished from prostrate knotweed by its coarser, more erect stems and broader,
more rounded leaves. All knotweeds have tough, deeply penetrating tap roots and thrive in
poor, compacted soils; they will even do well in cracks in concrete.

Mature

The flowers are very small and inconspicuous. They lack petals but usually have five pink to
purple, but occasionally green, sepals. The flowers are produced in leaf axils and are usually
at least partially enclosed by the ocrea. Each flower produces a tiny, triangular dark brown
seed that is surrounded by a papery hull.

% of fields
where found

Key features

Prostrate to semi-erect growth habit; long, wiry stems with swollen nodes covered with an
ocrea; tiny, pink-purple axillary flowers

Similar species

Striate knotweed Polygonum achoreum

Showy Milkweed

Asckpias speciosa

Family

Mill-cweed Asclepiadaceae

Seedling

The cotyledons are oblong and have a shiny undersurface. True leaves are opposite with
short hairs on the margin. Seedlings are rarely noticed in their roadside and pasture habitat.

Juvenile

Although showy milloveed is often listed as a poisonous species, livestock usually avoid it
unless they are starving. It tends to spread slowly by creeping rootstocks to form clumps.
Showy millcweed leaves appear greyish-green due to the soft hairs covering the surface.
Leaves are oblong and leathery-thick. They are oppositely arranged on the stem and have
very short petioles and stipules at the nodes. The whole plant is filled with a white, sticky
latex.

Mature

The beautiful pink and white flowers are arranged in large, rounded umbels. Each flower
has five outer petals and an inner five-pronged corona seated on the stamen tube. The
flower stalks are covered with white wooly hairs. Each flower develops into either one or
two large pods covered with wooly hairs and soft projections on the surface. The pod opens
on one side at maturity to release many reddish-brown, flattened seeds. Each seed is
equipped with a tuft of silky hair for wind distribution.

Key features

White, sticky latex in stem and leaves; opposite leaf arrangement; large, wooly-hairy
seedpods that have soft projections on the surface and open on one side only at maturity

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation ^

roadsides

forage crops, hay fields

turf

waste areas 4^^

Juvenile

Flower: round umbels

Infestation

Stork’s-bill

Erodium cicutarium

Other names

Redstem filaree

Family

Geranium Geraniaceae

Seedling

The three-lobed cotyledons of stork’s-bill
are unique. The true leaves are deeply and
pinnately divided into segments, which are
further lobed. Coarse, spreading hairs cover
surface.

Juvenile

Stork’s-bill has a tap root with stout lateral roots. The hairy stems are low and spreading,
forming tangled clumps. Basal leaves are petioled and pinnately compound with deeply cleft
leaflets. Stem leaves are fewer, smaller and sessile.

Mature

Flowers are in clusters, each with five pink-purple petals and five sepals with bristly tips.
The styles of the pistil are united and elongate into a column or long “bill,” hence the name
stork’s-bill. At maturity, the bill splits upward into five parts, each a one-seeded, long-tailed
segment attached to a slender brown seed. When the tail dries, it resembles a coiled spring.

Key features

Three-lobed cotyledons on seedling; low, spreading growth habit; distinct bill of the fruit
and coiled tail on the seed

% of fields
where found
0

M 16-50
50-1-

/S not
surveyed

Life Cycle I

annual

winter annual

biennial creeping perennial simple perennial

Habitat

conventional tillage
reduced tillage

forage crops, hay fields iA

rangeland A
irrigation
turf A

wetland

roadsides A
waste areas AAA

Water Smartweed

Polygonum amphibium
Family

Buclcwheat Polygonaceae

Seedling

Seedlings are not commonly seen.

Juvenile

This species has both aquatic and terrestrial forms. The aquatic form is usually found
growing in standing water while the terrestrial form is found in cultivated fields. Swamp
smartweed, Polygonum coccineum, is a related and very similar species that also has both
aquatic and terrestrial forms.

In cultivated fields, water smartweed is usually found in patches growing from extensive,
creeping rootstocks. The stems have swollen nodes with prominent ocreas. Growth habit is
erect or wealdy erect. Leaves are alternate and petioled. They have entire margins and are
approximately ovate, although shape varies. Leaves and stems are usually both hairy. The
terrestrial form has a distinct “skirt” or spreading collar extending from the upper edge of
the ocrea. The terrestrial form of swamp smartweed also has this feature. It is difficult to
distinguish between the two species before flowering.

Mature

Although individual flowers lack petals, the calyx is bright pink to scarlet. The spike-like
racemes are short and thick with hairless stalks below the inflorescence. The spike-like
racemes of swamp smartweed are longer and more slender with hairy stalks below the
inflorescence. Each flower produces one seed. Both species have brown to black, lens-
shaped seeds.

Key features

In patches growing from creeping rootstocks; swollen nodes with prominent ocreas that
may be “skirted”; bright pink to red flowers in spike-like racemes

Similar species

Swamp smartweed Polygonum coccineum

Mature

Juvenile

White

Flowered Species

Baby’s-breath

Gypsophila pankulata

Family

Pink Caryophyllaceae

Seedling

Cotyledons are linear. The true leaves are also linear, with entire margins and rounded tips.
The leaves emerge in pairs and appear greyish-green. Seedlings are not often noticed.

Juvenile

Baby’s-breath has a deep, penetrating root system. The plant is erect with freely-branching
stems that are smooth and swollen at the nodes. Stems and leaves are covered with
glandular hair to give a greyish-green, waxy “bloom.” The leaves are opposite, entire-
margined and linear to lanceolate with a single central vein.

Mature

Baby’s-breath plants resemble large, white powder puffs along prairie roadsides. The many
small, white-petalled flowers in an open-branched inflorescence give this delicate “puffy”
appearance. Each flower develops into a multi-seeded capsule containing tiny black, snail-
like seeds with minute bumps and ridges. The mature, brittle stem breaks at the base and
tumbles with the wind to distribute seed.

Key features

Cotyledons and true leaves of seedling resemble each other; greyish-green “bloom” on stems
and leaves due to glandular hair; delicate white “puffs” along prairie roadsides

Life Cycle

annual winter annual biennial creeping perennial simple perennial

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields ^

turf

waste areas

Mature

Infestation

Bladder Campion

Silene cucubalus

Family

Pink Caryophyllaceae

Seedling

The cotyledons and first true leaves resemble each other. They are oblong with entire
margins, hairless and emerge two at a time.

Juvenile

Bladder campion has a deep, branching tap root. Like dandelion, new bladder campion
plants can be produced if the crown of the plant is severed. Its much-branched stems are
erect with swollen nodes. Leaves are opposite, sessile and joined at the base. They are long
and narrow with a tapered tip. Both the stem and leaves are smooth and light green-to-
whitish due to a waxy covering or “bloom” on the surface.

Mature

Flowers are found in branching clusters at the top of the plant. Each flower has five deeply-
lobed white petals surrounded by a bladder-like calyx. The calyx may be light green or pink
with either darker green or purplish net veins. The round seed capsules have six teeth at the
top and are enclosed by the mature, loose, papery calyx. Seeds are Iddney-shaped, grey and
covered with tiny bumps. They are difficult to distinguish from the seeds of both white
cockle and night-flowering catchfly.

Key features

Deep, branching tap root; opposite leaves and stems with a waxy bloom; bladder-like green
or pink calyx

1 Life Cycle I

annual

winter annual

biennial

creeping perennial simple perennial

Habitat 1

conventional tillage
reduced tillage
forage crops, hay fields

rangeland 4^

irrigation

turf

wetland
roadsides
waste areas

Mature

Flower: with bladder-like calyx

Canada Fleabane

Erigeron canadensis

Other names

Horseweed

Family

Sunflower Asteraceae

Seedling

Canada fleabane has oval cotyledons and
bright green, hairy leaves.

Juvenile

The rosette leaves are bright green, softly hairy and
petioled. They are elliptical in shape and coarsely toothed.

Stems are erect and bristly-hairy. Stem leaves are alternate and often closely
crowded. Middle and upper leaves are linear, smaller than basal leaves and are more harshly
hairy than the young leaves. They taper to the stem and usually have no teeth on the
margins. Crushed leaves have a carrot-like odor. Canada fleabane is becoming more and
more frequent as a winter annual weed in fields with reduced tillage.

Mature

The numerous, fluffy-looking flower heads are on short branches at the top of the plant.
The central, yellow disk flowers are surrounded by outer ray flowers. The ray flowers are
white and may be partially or completely hidden by the several whorls of narrow, pointed
bracts around each flower head. The yellowish seeds are oblong and flattened with a white
pappus for wind dispersal.

% of fields
where found

Key features

Bristly-hairy stems and leaves; basal leaves toothed, upper leaves usually entire; numerous
fluffy flower heads

Life Cycle

annual winter annual

biennial

creeping perennial

simple perennial

Habitat

conventional tillage ^

rangeland ^

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Chickweed

Family

Pink Caryophyllaceae

Stellaria media

Seedling

Cotyledons are narrowly oval with a
pinched tip. The first true leaves are
opposite and broader than the cotyledons,
although they too have a pinched and
pointed tip.

Juvenile

Chiclcweed is low-growing with bright green, much-
branched stems. Plants often form dense mats that are highly
competitive with crop and garden plants. The stems may root at the nodes,
making this weed very difficult to hand-pull. They are smooth except for a single row of
fine, white hair. The opposite leaves also have a row of hair on the petioles. Leaves on the
upper stems are usually stalldess. Chiclcweed can be distinguished from a related species,
mouse-eared chiclcweed, by the leaves. In the latter species, the leaves are sessile and
densely-hairy all over, resembling the ear of a mouse.

Mature

The small, star-shaped flowers are located at the tips of the stems or in branch axils. The
flowers have five white, deeply-notched petals that are shorter than the surrounding hairy
sepals. Each flower opens for only one day before a fruit develops. The seed capsules are
egg-shaped and open by six teeth. Nearly round, reddish-brown seeds with a bumpy surface
are produced throughout the growing season.

% of fields
where found

i;E 0

■I 5-15
1 16-50
r 50-1-

: not

surveyed

Key features

Low-spreading growth habit; single row of hairs on the stems and leaf petioles; tiny, star-
shaped flowers

Similar species

Mouse-eared chiclcweed Cerastium vulgatum

Life Cycle

annual winter annual

biennial

creeping perennial

simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields ^

turf ^

waste areas

Cleavers

Galium aparine

Other names

Bedstraw

Family

Madder Rubiaceae

Seedling

Cotyledons are petioled and oblong with a
notched tip. The first true leaves are
narrow with a pointed tip, sessile and
arranged in a whorl of four.

Juvenile

Cleavers has numerous, freely-branched stems that are
weak and straggly. The plant has difficulty standing upright and is more
often found lying on nearby vegetation. Stems are four-sided and covered with stiff,
baclcward-pointing hairs that allow them to adhere to plants, animals and people alike.

The leaves produced at this stage are usually in whorls of six to eight and are also covered
with prickle-like hair. A close relative of cleavers, called false cleavers, has been identified
in some areas of Alberta and Saskatchewan. While very similar in appearance, false cleavers
can be distinguished by the leaves, which are notched at the tip. Both species are equally
troublesome and difficult to control in crops.

Mature

Tiny, greenish-white flowers are located in clusters of two to five in leaf axils. While the
flowers are very inconspicuous, they produce unique-looking fruits that appear as two
seeds joined together. The weed’s common name is derived from the fact that these two
seeds break apart or “cleave” at maturity. Each greyish-brown seed is nearly round and
covered with hooked bristles. They are similar in size to canola and are very difficult to
screen out of that crop.

% of fields
where found
0

5-15

■

16-50

50-1-

not

surveyed

Key features

Narrow leaves with pointed tips arranged in whorls; weak, four-sided stems with prickly
hair; fruits formed of two seeds joined together

Similar species

False cleavers Galium spurium

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation ^

roadsides

forage crops, hay fields

turf

waste areas

life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

Common Pepper-grass

Lepidium densiflorum

Other names

Pepperweed, green-flowered pepper-grass

Family

Mustard Brassicaceae

Seedling

Common pepper-grass has linear cotyledons with rounded tips. The first true leaves are
petioled with deeply and irregularly lobed margins.

Juvenile

The leaves of the basal rosette are deeply and irregularly lobed with some variation from
plant to plant. The stem is erect, covered with short hairs and very branched, especially near
the top of the plant. Stem leaves are alternate, sessile and linear to lanceolate in shape. The
margins are entire or occasionally toothed.

Mature

Common pepper-grass is not usually noticed until the pods are formed. The flowers are in
a raceme, but are very inconspicuous as they often lack petals. Even if tiny white petals are
present, they are shorter than the calyx, hence the other name “green-flowered pepper-
grass.” The tiny seedpods are densely packed on the raceme. They are nearly round,
flattened and notched at the top with a tiny bump in the middle of the notch. There are two
seeds per pod, one on each side of the membranous wall inside the pod. The flattened,
oblong seeds are bright reddish-yellow. At maturity, the brittle stem breaks off, and the plant
rolls along the ground to scatter seed.

Key features

Basal rosette of petioled leaves with irregularly and deeply lobed margins; dense racemes of
tiny, green seedpods; pods with two seeds

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage 4^

rangeland

wetland

reduced tillage 4^^

irrigation

roadsides 4^

forage crops, hay fields 4f^

turf

waste areas 4^^

Corn Spu

Spergula arvensis

Family

Pink Caryophyllaceae

Seedling

Both cotyledons and true leaves are needle-
like, erect and bright green. The true leaves
emerge in whorls of at least three leaves per
node.

Juvenile

Corn spurry may resemble young plants of field horsetail, a perennial weed that
grows in a similar habitat. Unlike corn spurry, the stems of field horsetail are jointed with
black-tipped bracts surrounding the nodes. It also has whorled branches, unlike the
individual whorled leaves of corn spurry. The stems on corn spurry are bright green and
have surfaces that range from smooth to finely hairy or even sticky in texture. The linear,
somewhat fleshy leaves typically occur in whorls of six to ten, with small stipules below.
The leaves appear either flat or slightly rounded in cross-section. Young corn spurry plants
often exhibit a low, sprawling habit whereas fully grown plants may be either erect or
spreading with single or much-branched stems.

Mature

Flowers are very small, but often numerous, and in clusters at the end of branches. The
flowers are short-stalked and have five green sepals joined at the base and five white petals.
The fruits are tiny capsules that tend to point downward at maturity. They split into five
divisions to release small black, nearly round, flattened seeds. The seeds typically have a
narrow white wing around the margin as well as whitish projections on the surface that
resemble tiny pieces of chaff.

Key features

Bright green color; needle-like leaves; whorled leaf arrangement

|. Life Cycle

annual winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Death Camas

Zygadenus gramineus

Family

Lily Liliaceae

Seedling

Seedlings are seldom noticed.

Juvenile

Death camas is extremely poisonous to livestock and humans. The related, more robust
white camas is also poisonous, but less so. The early spring growth of both species is grass-
like from the underground bulb that is particularly toxic. Both species are more likely to
cause problems in the spring because the bulb may pull out more easily when the ground is
wet. The long, narrow leaves of both species are keeled making them V-shaped in cross-
section. Before flowering, death camas or white camas could be confused with prairie
onion, which has U-chanelled leaves and a distinct onion smell when bruised. Death camas
and white camas leaves do not have the strong onion odor.

Mature

The flowers of death camas are small with six creamy-white to yellow petals. They are
arranged in a raceme that may be branched at the base. Flowers of the more showy white
camas are larger, creamy-white to green in a less dense raceme that is unbranched at the
base. White camas has a green, heart-shaped gland on each segment of the flower that can
be used to distinguish it from death camas, which has a semicircular gland. Flowering
plants should be easily distinguished from wild onion species, which have white or pink
flowers arranged in simple umbels. The three-lobed capsule of death camas is elliptical and
contains many seeds.

Key features

Long, narrow leaves V-shaped in cross-section; underground bulb; raceme of creamy-white
to yellow flowers

Similar species

White camas Zygadenus elegans; prairie onion Allium textile

Life Cycle

annual winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland ^

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Mature

Capsules

Similar species! Wlntecamas- flowers

^ ...

. 4

\ —

* #»?

1' V-' -a 1

■■ ■ c

■*

Knapweed

Family

Sunflower Asteraceae

Diffuse

Centaurea diffusa

Seedling

Cotyledons are oval with short stalks. The first few true leaves are oblong with an entire
margin while later leaves have shallow lobes.

Juvenile

Diffuse knapweed produces an elongated tap root and a rosette of much-divided, feathery-
looking leaves. In contrast, the leaves of spotted knapweed are deeply lobed into narrow
segments. The leaves of both species are covered with a thin layer of matted, wooly hair
resembling a cobweb. Stems are erect, much-branched and hairy. Upper stem leaves are
bract-like and entire. Although diffuse knapweed is not considered poisonous, it is
extremely bitter-tasting and generally avoided by grazing animals. Both species of
knapweed have almost formed monocultures in rangeland throughout parts of the British
Columbia interior. Consequently, a major campaign is underway to minimize their spread
into the prairies.

Mature

Numerous narrow heads are produced singly at the ends of branches. The flowers are
generally white but occasionally pink-purple. They are surrounded by pale yellowish-green,
triangular bracts ending in a stiff spine. The involucral bracts are a key way to distinguish
diffuse knapweed from its relatives, spotted knapweed and yellow star-thistle. Spotted
knapweed heads have bracts with a black-tipped fringe while the bracts on yellow star-
thistle heads are modified into slender, sharp spines. The seeds of diffuse knapweed are
narrowly oval, light brown-to-black and lack a pappus.

Key features

Much-divided, “cobwebby” basal leaves; generally white flowers; triangular, spine-tipped
bracts

Similar species

Yellow star-thistle Centaurea solstitialis

Life Cycle

annual

winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland

^ wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Flower: head, showing spine-tipped bracts

Infestation

Juvenile: rosem

Mature

Field Bindweed

Convolvulus arvensis

Family

^Io^ning-glon^ Convolvulaceae

Seedling

Cowledons are broad with a notched tip and ^^sible venation. The true leaves are entire,
petioled and arrow-shaped with blunt tips. Field bindweed is sometimes confused with wild
buckwheat, which also has arrow-shaped leaves. However, wild buckwheat has linear
cotyledons and more pointed leaf tips.

Juvenile

Field bindweed has persistent, spreading, white cord-like roots with buds that produce new
shoots. Branched stems twine around the crop or form prostrate mats if there is no crop for
support. Leaves are alternate, petioled and generally arrow-shaped with blunt tips. There
is considerable variation in the overall leaf shape and the shape of the basal lobes. Wild
buckwheat is also a uHning plant and is often confused with field bindw^eed. However, wild
buckwheat has ocreas at the stem nodes, and its arrowy-shaped leaves tend to have more
pointed tips.

Mature

Flow’ers are showw, wyhite to pinkish and funnel-shaped with long stalks. Each flower lasts
only one day. Flow^ers are usually solitar\y on stalks from leaf axils or in small groups. There
is a pair of small narrowy bracts on the flowyer stalks. Each flower produces a seed capsule
with one to four seeds inside. The seeds are pear-shaped, appear dull grey-brown and have
tiny bumps on the surface.

Key features

Twining stems; arrow-shaped leaves with blunt tips; funnel-shaped, white to pinkish flowers
with long stalks

Life Cycle

annual winter annual biennial creeping perennial simple perennial

Habitat

conventional tillage 4^

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields ^

turf

waste areas

Seedlinq

Juvenile

Hairy Nightshade

Solamm sarrachoides

Other names

Cupped nightshade

Family

Nightshade Solanaceae

Seedling

Cotyledons are stalked and narrowly oval with distinctly pointed tips. The first true leaves
are ovate with wavy margins.

Juvenile

Hairy nightshade has stems that are usually erect but much-branched and spreading.
Leaves are ovate to triangular with margins that range from entire to wavy and even
toothed. As the name suggests, the entire plant is covered with dense, short hair as well as
long, glandular hair making it sticky to the touch. Hairy nightshade is easily confused with
black nightshade at the juvenile stage. While both species are hairy, black nightshade lacks
the more prominent, sticky hairs.

Mature

The star-shaped flowers are smaller but closely resemble those of potato and tomato. They
occur in axillary clusters of three to ten. The petals are either white or white tinged with
purple. Each flower produces a berry that is initially green but turns yellowish-brown when
fully ripe. The berries are partially surrounded or cupped by the sepals. Inside each berry
are numerous light brown, tomato-like seeds. Once the fruits are formed, it is very easy to
tell this weed from black nightshade. The berries of black nightshade are purple to black at
maturity and are not cupped by the sepals. In both cases, people should avoid eating the
immature green fruits since they are known to be highly poisonous.

Key features

Ovate to triangular leaves; long, glandular hairs that make plants sticky to the touch;
yellowish-brown, cupped berries

Similar species

Black nightshade Solanum nigrum

Life Cycle

annual winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation ^

roadsides

forage crops, hay fields

turf

waste areas

Juvenile

Mature

Narrow-leaved

Milk-vetch

Astragalus pectinatus

Family

Pea Fabaceae

Seedling

Seedlings of narrow-leaved milk-vetch are frequently overlooked in its rangeland habitat.

Juvenile

Narrow-leaved milk-vetch has a deep, stout tap root and an underground woody stem.

Aerial stems are weakly erect to spreading, reddish at the base and found in clumps. The
compound pinnate leaves usually have from nine to seventeen leaflets. The leaflets are
linear and very narrow with flattened hairs. Pointed stipules are found at stem nodes. The
whole plant has a distinctly unpleasant odor. It is unpalatable and therefore unlikely to
poison livestock unless there is a severe shortage of forage. This species is a good indicator
of high selenium soils.

Mature

Bloom occurs in late May to early June. Racemes are located in upper leaf axils. The pea-
type flowers are cream-colored to pale yellow. Each flower forms a fleshy pod that is circular
in cross-section. The pod becomes very dry and hard at maturity. The irregular, kidney-
shaped seeds are tan to reddish-brown.

Key features

Clumps of weakly erect stems; unpleasant odor; compound pinnate leaves with narrow,
linear leaflets

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland ^

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Juvenile

flowering raceme

Night-flowering

Silene noctiflora

Catchfly

Other names

Sticky cockle

Family

Pink Caryophyllaceae

Seedling

Cotyledons are smooth and oblong. The
first true leaves emerge two at a time and
have dense, short hair on the surface and
margins. This seedling is easily confused with
bluebur. The true leaves of bluebur emerge one at
a time and have a distinct crease down the center. In
addition, bluebur cotyledons have a small “bump” at the
tip.

Juvenile

Night-flowering catchfly often forms a rosette of opposite, densely-hairy leaves. They are
wide at the tip with entire margins and broad but short petioles. These lower leaves are
usually not sticky to the touch. Stems are erect with swollen nodes. They may branch
sparingly near the top of the plant. Leaves on the upper plant are sessile and narrower at
the tip than the basal leaves. The upper stems and leaves are covered with sticky, glandular
hairs.

Mature

The flowers have five white-to-pink, notched petals and are usually open in the evening.

The petals are enclosed in a sticky-hairy, tubular calyx with ten branched veins. Each flower
produces a light brown capsule with six teeth at the top. Inside are many grey, kidney-
shaped seeds covered with rows of minute bumps. The seeds are a frequent contaminant of
timothy and alsike or red clover seed. Night-flowering catchfly is often mistaken for its close
relative, white cockle, which is a biennial and not sticky to the touch. The calyx of white
cockle has veins that are less-branched than night-flowering catchfly, and it forms a capsule
opening by ten teeth.

% of fields
where found

1-4

5-15

16-50

50-1-

■

not

surveyed

Key features

Opposite, hairy leaves; sticky upper stems and flowers; a branched-veined calyx

Life Cycle

annual winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage 4^^

irrigation

roadsides

forage crops, hay fields ^

turf

waste areas

Mature

Juvenile: nsem

Ox-eye Daisy

Chrysanthemum leucanthemum

Other names

White daisy

Family

Sunflower Astemceae

Seedling

Cotyledons are oval and stalkless. The first true leaves are broadly oval in shape with wavy,
lobed margins.

Ox-eye daisy has shallow, short, creeping roots. A basal rosette is produced in the first year.
The rosette leaves are petioled, spoon-shaped and coarsely-toothed. They are dark-green
and have a smooth, almost shiny surface. Tall, sparsely-branched stems emerge in the
second year from a thick crown. They are typically smooth, but may be sparingly hairy at
the base. The upper stem leaves are narrower and more deeply-toothed than the basal
leaves. They are sessile and often clasp the stem. All parts of the plant have a strong,
unpleasant odor.

Numerous yellow disk and white ray flowers occur in dense, showy, daisy-like heads.
Ox-eye daisy heads resemble those of scentless chamomile. The two weeds are easily
distinguished by the spoon-shaped leaves and strong odor associated with ox-eye daisy.
Each of the tiny disk flowers in the center of the head produces a single seed. The seeds
are narrow and black with ten prominent white ribs. They have a small projection on one
end, but lack the feathery pappus typical of many oih&t Astemceae weeds.

Short, creeping roots; spoon-shaped, coarsely-toothed basal leaves; strong, unpleasant odor

Juvenile

lUlature

Key features

annual

winter annual

biennial creeping perennial simple perennial

wetland
roadsides
waste are

reduced tillage

irrigation

turf

forage crops, hay fields

waste are

Juvenile: rosette

Pygmyflower

Androsace septentrionalis

Other names

Fairy candelabra

Family

Primrose Primulaceae

Seedling

The young seedling is extremely tiny and could easily be overlooked. It has tiny, oval
cotyledons and sessile leaves.

Juvenile

The rosette is very tiny. It has elliptical leaves that are either hairless or covered with
minute hairs. The leaf margins are usually entire but may be partly toothed. This plant is
seen in early spring in stubble fields and gardens. Wood whitlow-grass has a tiny rosette
and is found in a similar habitat. It can be distinguished from pygmyflower because it has
branching hairs on the leaves.

Mature

Although several flowering stems arise from the rosette, usually one flowering stem is more
well-developed than the others. The tiny white flowers are arranged in a simple umbel with
bracts at the base. Each flower is tubular with five lobes that are slightly notched at the tip.
When the petals fall, the five pointy lobes of the calyx resemble a tiny green star. Each
flower develops into a many-seeded capsule.

Key features

Tiny leaves, flowers and overall short stature of the plant; early spring bloom; bracts at the
base of the white-flowered umbel

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland 4^

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields ^

turf

waste areas ^

Juvenile; rosette

Mature

Round-leaved Mallow

Malva rotundifolia

Other names

Cheeseweed

Family

Mallow Malvaceae

Seedling

Cotyledons are distinctly heart-shaped with
a rounded tip and prominent veins. The first
true leaves are long-stalked and round to
kidney-shaped.

Juvenile

Round-leaved mallow is a low, spreading plant with long, much-branched, hairy
stems. In densely populated areas, however, stems may be much more upright, even erect.
The leaves at this stage usually appear five-lobed with a toothed margin. The teeth on the
margin are frequently rounded at the tip, making the leaves look almost scalloped. They
may be either smooth or sparingly hairy. The upper leaf surface has pronounced palmate
venation and a wrinkled texture. There are small green stipules at the stem nodes.

lUlature

Tiny, white or pale blue flowers are found in axillary clusters of one to three. Each flower
produces a circular, disk-like fruit. Inside the fruit, seeds are arranged in a ring somewhat
resembling the sections in an orange. Individual seeds are brown and wedge-shaped with
a rough, pitted surface.

% of fields
where found
0

1-4
5-15
16-50
50-1-
not

surveyed

Key features

Round to kidney-shaped leaves with long petioles; long, spreading or erect much-branched
stems; circular fruit with wedge-shaped seeds

Life Cycle

annual winter annual

biennial

creeping perennial

simple perennial

Habitat

conventional tillage

rangeland 4^

wetland

reduced tillage 4^^

irrigation

^ roadsides

forage crops, hay fields

turf

waste areas

101

Scentless Chamomile

Matricaria perforata

Other names

Scentless mayweed

Family

Sunflower Asteraceae

Seedling

Cotyledons are oval and sessile. The first
true leaves are deeply-divided, often into
five distinct segments. Both cotyledons and
true leaves are smooth. Seedlings may be
easily confused with flixweed. Flixweed
cotyledons are stalked and narrower than scentless
chamomile. In addition, the true leaves of flixweed are
usually tri-lobed and hairy.

Juvenile

Scentless chamomile forms a rosette of finely-divided leaves. The leaves are almost fleshy
in texture and have no odor when crushed. The sometimes confusing wild chamomile and
pineappleweed have a pleasant aroma while ox-eye daisy and stinking mayweed both have
a distinctly unappealing scent. In addition, ox-eye daisy can be distinguished from scentless
chamomile by its spoon-shaped, lobed leaves. The stems produced by scentless chamomile
are erect, smooth and often much-branched.

Mature

Small, daisy-like heads are found singly at the ends of the branches. Each head has tiny
yellow disk flowers in the center surrounded by flat, white ray flowers. When the heads are
ripe, the white flowers tend to point backwards, giving the entire head the appearance of a
badminton shuttlecock. At first glance, the heads of wild chamomile look very much like
scentless chamomile. With closer inspection, it is possible to see that the receptacle of
scentless chamomile is more rounded than the conical-shaped receptacle of wild chamomile.
Each yellow flower produces a seed that is dark brown with three white ribs on one side.

The seeds do not have a hair-like pappus.

Key features

Finely-divided leaves; noticeable lack of odor; daisy-like heads at full maturity resemble a
badminton shuttlecock

Similar species

Wild chamomile Matricaria chamomilla\ stinking mayweed An t/zemzs cotula

Habitat

conventional tillage

rangeland

reduced tillage

irrigation ^

forage crops, hay fields

lutf ^

wetland

roadsides

% of fields
where found

5-15

16-50

50+

not

surveyed

Life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

waste areas

103

Shepherd’s-purse

Capsella bursa-pastoris

Family

Mustard Brassicaceae

Cotyledons are oval to ovate with rounded
tips. The first true leaves are entire to slightly
lobed. Subsequent leaves have variable margins.
Leaves are petioled and covered with star-shaped
hairs intermingled with unbranched hairs.

Juvenile

The basal rosette leaf margins vary from slightly to deeply lobed. They can even be divided
to the midrib. The extreme variability of the leaf margins can cause confusion when
identifying this weed. Stems of shepherd’s-purse are sparsely branched and usually covered
with star-shaped hairs. Stem leaves are alternate, sessile and linear to lanceolate with entire
margins or a few scattered teeth. The basal lobes of the leaves are pointed and clasp the
stem.

Mature

The raceme is made up of small white flowers, each with four petals. The pod developing
from each flower is triangular and flat. There is a notch at the tip with a small beak in the
centre of the notch. Seeds are attached to both sides of the membranous wall inside the
pod. The seeds are oblong, appear orange to reddish and have a pitted surface.

% of fields

wliere found

B3 14

1 16-50
50-1-
not

surveyed

Key features

Star-shaped hairs on leaves and stems; upper leaves that clasp the stem with pointed basal
lobes; triangular, flat seedpods

Life Cycle

annual winter annual biennial creeping perennial simple perennial

105

Spotted Water-hemlock

Cicuta maculata

Family

Parsley Apiaceae

Seedling

Seedlings are seldom noticed.

Juvenile

Spotted water-hemlock is extremely poisonous to humans and livestock. Stock poisonings
often occur in the spring when young plants are more easily pulled out of the ground. The
poison is an oily liquid called cicutoxin that is found mainly in the fleshy roots and in
horizontal cavities at the base of the stem. The tall, erect stem has purple spots or streaks.
Spotted water-hemlock is often confused with the related but non-poisonous water-parsnip,
Sium suave. Both species thrive in wet, marshy habitats. The leaves of water-parsnip are
compound pinnate with finely toothed leaflets. In contrast, spotted water-hemlock leaves
are twice-compound pinnate with coarsely toothed leaflets. Leaves are alternately arranged
on the stem and have flared petioles at the base.

Mature

The tiny white flowers of both species are grouped into compound umbels. There are
usually no bracts at the base of the main umbel of spotted water-hemlock, but there could
be one or two. On the other hand, water-parsnip has several to many pointed bracts at the
base of each main umbel. An individual flower can produce two brown seeds. Each seed has
five ribs on one surface and is flat on the other side.

Key features

Purple-streaked stem; twice-compound pinnate leaves with coarsely toothed leaflets; bracts
usually absent under main umbel

Similar species

Water-parsnip Sium suave

Life Cycle

annual winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

107

Stinkweed

Thlaspi arvense

Other names

Penny cress, Frenchweed

Family

Mustard Brassicaceae

Seedling

Cotyledons are oblong with short stalks.

The first true leaves are also oblong and
have a smooth surface. Stinkweed may be
distinguished from shepherd’ s-purse at the seedling
stage by the absence of hair on the true leaves.

Juvenile

StinWeed typically forms a basal rosette. The rosette leaves are petioled and have an entire
to wavy margin. They give off a distinctive, strong, turnip-garlic odor when crushed. Stems
are smooth, erect and often branched above. The upper stem leaves are smaller than the
rosette leaves and have shallow, irregular teeth. They are sessile and often clasp the stem.
Plants turn yellow soon after flowering.

Mature

Tiny, four-petalled white flowers are located in racemes at the tops of branches. Each flower
produces a circular, flattened seedpod with “wings” and a narrow, deep notch at the top. At
maturity, the seedpods turn brown and split open to reveal oval, reddish-brown to black
seeds. The seeds are covered with rows of concentric ridges and resemble a human
fingerprint.

% of fields
where found
0

1-4
5-15
16-50

50-1-
not

surveyed

Key features

Smooth surface of leaves and stems; turnip-garlic odor; flattened, winged, notched seedpod

annual

winter annual

Life Cycle

biennial creeping perennial simple perennial

conventional tillage
reduced tillage
forage crops, hay fields

rangeland
irrigation
turf

wetland
roadsides
waste areas

WWl^V. flowers and seedpods on raceme

Juvenile: rosette

Mature

White Clover

Trifolium repens

Other names

Dutch clover

Family

Pea Fabaceae

Cotyledons are oval, and the first true leaf is long-stalked with a single blade indented at the
tip. All subsequent leaves produced are trifoliolate.

Juvenile

White clover is a shallow-rooted plant with extensive, creeping stems. When the stem nodes
encounter the ground, they frequently root to form new shoots. The trifoliolate leaves are
characterized by very long petioles. The three leaflets are somewhat variable in shape, but
typically broadest at the tip, which is often shallowly-notched. There is usually a pale,
inverted V-shaped mark on the upper surface of each leaflet, but no hair. Each leaf has a
pair of small, pointed stipules at the base that form a tube around the stem. While white
clover is an important legume species in certain parts of Canada, in the prairies, it grows
mostly as a weed of turfgrass.

Mature

Dense, round, head-like racemes are produced on long stalks. Each raceme contains
between 20 and 40 white to pinkish pea-like flowers. The flowers form small pods with two
to five squarish, yellow seeds.

Key features

Extensive creeping stems; trifoliolate leaves with leaflets having an inverted V-shaped mark
and shallow notched tip; dense, head-like racemes of white to pinkish pea-like flowers

1 Life Cycle I

annual

winter annual

biennial

creeping perennial simple perennial

1 Habitat 1

conventional tillage
reduced tillage 4^
forage crops, hay fields

rangeland 4^
irrigation

M^4fr

wetland
roadsides
waste areas

110

Ill

White Cockle

Silene alba

Family

Pink Caryophyllaceae

Seedling

Cotyledons are stalked, ovate in shape and somewhat constricted at the tips. The true
leaves are softly hairy on both surfaces and margins. They are oppositely arranged,
elliptical and have short, hairy petioles.

Juvenile

White coclde has a fleshy tap root and forms a rosette in the first year. Stems are erect,
covered with hair and swollen at the nodes. The middle and upper leaves are sessile,
opposite, elliptical and softly hairy. The stems and leaves of white coclde are not sticky
to the touch like those of night-flowering catchfly.

Mature

The flowers of white cockle are large and showy, each with five notched white petals.
Flowers on one plant are either all male or all female. The calyx surrounding male flowers
is hairy with ten veins. The hairy calyx of female flowers has twenty veins, five of which are
very distinct, the others less so. The female flower forms a light brown capsule that opens
with ten teeth. The seeds are greyish, bumpy and kidney-shaped. Night-flowering catchfly
has calyx veins that are more distinctly branched than white cockle. Also, the capsule of
night-flowering catchfly opens with only six teeth. The overall stickiness of mature night-
flowering catchfly is the easiest way to distinguish it from white cockle.

Key features

Opposite, softly hairy leaves; swollen nodes; large, white, showy flowers; capsule opening
by ten teeth

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas ^

112

Infestation

Juvenile

Mature

113

Wild Buckwheat

Polygonum convolvulus

Family

Buclovheat Polygonaceae

Seedling

Cotyledons are linear and positioned at
120 degrees from each other. Tartary
buckwheat can be distinguished at the seedling
stage by its round cotyledons. The true leaves of
wild buckwheat are arrow-shaped with pointy tips and
pointed basal lobes. Leaves are alternately arranged and petioled
with entire margins.

Juvenile

Wild buclcwheat is tap-rooted and has a twining growth habit. The slender stem branches
near the base and has ocreas at the stem nodes. The vines become entangled with the crop,
causing lodging and making harvest difficult. Tartary buckwheat can be distinguished by its
erect stems. Field bindweed, also a twining weed, has perennial, creeping rootstocks and
lacks ocreas at the stem nodes.

Mature

Small flowers are produced in axillary and terminal racemes. In contrast, flowers of field
bindweed are large and showy with white to pink funnel-shaped corollas. Although wild
buclovheat flowers lack petals, there are five whitish-green sepals that tightly enclose a
single seed. Each seed is dull, dark brown to black and triangular in cross-section. Tartary
buclcwheat seeds protrude from the sepals and are larger than seeds of wild buckwheat.

% of fields
where found
0

■ '£ 1-4
Hi 5-15
Hi 16-50
50-1-
not

surveyed

Key features

Twining stems; ocreas at stem nodes; arrow-shaped leaves with pointy tips

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

115

Wild Caraway

Carum carvi

Family

Parsley Apiaceae

Seedling

Seedlings are not commonly seen in the field.

Juvenile

Wild caraway produces a large brown tap root and lacy-looking rosette in the first year.

Tall, smooth, slender stems emerge from the crown the following spring. Each stem has
pinnately compound leaves with leaflets that are once or twice divided into narrow,
threadlike segments. This weed is a relatively new problem on the prairies, but has been
found moving into ditches and roadsides adjacent to cultivated land.

Mature

Tiny white flowers are located in loose, compound umbels found at the top of the plant
and at the ends of side branches. Wild caraway is sometimes mistaken for its relative,
wild carrot. The two species can be distinguished easily by the bracts found beneath the
inflorescence. Wild caraway is either bractless or has only one to three bracts while wild
carrot has a distinct whorl of bracts, many of which are further divided. Wild caraway also
tends to flower in spring or early summer, which is much earlier than wild carrot. The seeds
of wild caraway are oblong, brown with five tan ribs and conspicuously scented.

Key features

Large, brown tap root; smooth pinnately compound leaves with leaflets of threadlike
segments; white-flowered compound umbels with few or no bracts beneath

Similar species

Wild carrot Daucus carota

Life Cycle

annual

winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland ^

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

116

Infestation

Seedlin

Mature

117

Wild Licorice

Glycyrrhiza kpidota

Family

Pea Fabaceae

Seedling

Cotyledons are oblong and thickened. The first two true leaves have a single, oval blade
on a short stalk. The surface of the leaves is covered with minute depressions while the
margins have short, scattered hairs. All the remaining leaves produced are trifoliolate.

Juvenile

Tall, erect, somewhat hairy stems arise from extensive, deep, creeping roots. The roots are
highly aromatic when dug up, and the distinctive licorice scent gives this weed its common
name. Leaves are pinnately compound with 11 to 19 elongated leaflets. The leaflets are
broadest in the middle and have a prominently pointed tip. They are smooth on the upper
surface with tiny, glandular dots on the underside.

Mature

Wild licorice forms erect, dense racemes on short stalks in the axils of upper leaves. The
flowers are yellowish-white and pea-like in structure. Each flower forms a reddish-brown
pod covered with hooked bristles and resembles a bur. The pods contain three to five large
seeds.

Key features

Aromatic creeping roots with licorice scent; pinnately compound leaves with
11 to 19 leaflets, glandular-dotted below; reddish-brown bur-like pods

Life Cycle

annual

winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides ^

forage crops, hay fields

turf

waste areas ^

118

Mature

Infestation

119

Wild Tomato

Solamm triflorum

Other names

Cutleaf nightshade

Family

Nightshade Solanaceae

Seedling

Cotyledons are linear with a deep,
noticeable midrib. The first true leaves have
petioles and are ovate with wavy margins.

Juvenile

Wild tomato is a low spreading, mat-forming weed. Its stems are

usually branched at the base and may have a smooth or slightly hairy surface.

Older leaves are deeply lobed and typically sparsely hairy.

Mature

The flowers on wild tomato look very much like the flowers of its domestic relatives, tomato
and potato. They are usually found in clusters of three in leaf and branch axils. Each flower
has five white petals joined together in the shape of a star. The flowers produce smooth,
round, green berries resembling minature green tomatoes. As tempting as they may be, the
berries should not be eaten since there have been some reports of people being poisoned by
them. Inside each berry are light brown, ovate seeds that look exactly like tiny tomato
seeds.

Key features

Low spreading, mat-forming growth habit; deeply lobed leaves, tomato-like flowers and
berries

% of fields
where found

5-15

16-50

50-1-

■

not

surveyed

Life Cycle

annual winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage 4^^

irrigation

roadsides

forage crops, hay fields

turf

waste areas

120

121

Yellow

Flowered Species

Absinth

Artemisia absinthium

Other names

Wormwood

Family

Sunflower Asteraceae

Seedling

Cotyledons are ovate and short-stalked.

The true leaves are covered with fine
silvery hairs. The margins have rounded-to-
blunt lobes. Leaves have a strong sage-like
odor. Young seedlings of biennial wormwood may
appear similar but have sharply-toothed lobing on the
true leaves.

Juvenile

Absinth has a fibrous root system and develops a large rosette with long-petioled basal
leaves. Leaf blades are deeply divided into many oblong, blunt-tipped segments. The
covering of long silky hairs gives the leaves a light greenish-grey appearance. Stems are tall,
erect and hairy. Leaves on the stem are alternate and decrease in hairiness towards the top
of the plant. Upper leaves are almost sessile. They are much smaller than the basal leaves
and have fewer lobes or none.

Mature

Flower heads are small, numerous and droop from short stalks in the leaf axils of upper
branches. Each head holds many yellowish flowers, each capable of producing one seed.
The receptacle and several whorls of bracts are densely hairy. Seeds are shiny brown with
fine, white streaks and lack a pappus. Older plants become woody at the base. Absinth can
be controlled by cultivation but can be weedy in overgrazed pastures and hay fields. It can
produce tainted milk, and the pollen causes discomfort to some people.

% of fields
where found
0

m 1-4

■i S-15
■1 16-50
50-F-

"A-Mi not

surveyed

Key features

Light greenish-grey leaves due to long silky hairs; leaf margins with rounded or blunt lobes;
strong, sage-like odor

Similar species

Biennial wormwood Artemisia biennis

124

125

Argentine Canola

Brassica napus

Family

Mustard Brassicaceae

Seedling

Cotyledons are broad and kidney-shaped. The undersides are smooth, in contrast to the
wrinkled undersides of Polish canola cotyledons. The petioled leaves emerge one at a time.
They have irregularly lobed margins and are usually hairless. The leaves are bluish-green
and have a waxy surface.

Juvenile

Leaves of the basal rosette are large and irregularly lobed with the terminal lobe much larger
than lobes near the base of the leaf. As in the seedling, they appear bluish-green and waxy.
The stem is usually branched but less so than Polish canola. Typically, Argentine canola has
about six branches. The stem leaves of Argentine canola are alternate, entire or sparsely
toothed. The upper leaves are sessile and partially clasp the stem. Upper leaves of Polish
canola fully clasp the stem.

Mature

The flowers are produced in terminal and axillary racemes. Each flower has four bright
yellow petals. The petals are larger and lighter in color than Polish canola petals. The
unopened, green flower buds on the raceme are visible above the opened flowers. Unopened
flower buds of Polish canola remain below the opened flowers. Each flower produces a long,
narrow pod with a membrane in the middle and seeds on either side. There is a short beak
at the top of the pod. At maturity, the pods shatter easily to release seed. Seeds are
spherical, brown to black and have a minutely rough surface. They are larger than Polish
canola seeds.

Key features

Waxy, bluish-green leaves; upper stem leaves sessile but not fully clasping the stem;
unopened flower buds visible above opened flowers

126

Juvenile

Mature

127

Ball Mustard

Neslia paniculata

Family

Mustard Brassicaceae

Seedling

Cotyledons are petioled and almost round
with shallow indentations at the apex. The
first true leaves are oblong with round to
slightly pointed tips.

Juvenile

Ball mustard forms a rosette of long, narrow leaves with entire or nearly entire
margins. Stems are erect and often much-branched. The upper leaves are more arrow-
shaped than the basal leaves and clasp the stem. The entire plant. is usually covered with
small, star-shaped hairs.

Mature

Bright yellow flowers are located in dense racemes at the ends of stems. Each flower is four-
petalled and produces the characteristic ball-like seedpod that gives this weed its common
name. The seedpods are long-stalked and yellowish-brown with a dimpled surface. Each
pod contains a single seed although they rarely break open to expose the seed. Ball mustard
seeds are difficult to separate from the seeds of Argentine canola.

Key features

Entire or nearly entire leaves; star-shaped hairs over the entire plant; ball-like seedpods

% of fields
where found
0

■H 5-15
Hi 16-50
50-1-
not

surveyed

Life Cycle I

annual

winter annual

biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

128

129

Black Henbane

Hyoscyamus niger

Family

Nightshade Solanaceae

Seedling

Cotyledons are long-stalked and oval with rounded tips. The first true leaves are ovate with
wavy margins.

Juvenile

Black henbane typically develops a large tap root and basal rosette in the first year. The
leaves are sessile and generally ovate to oblong with an irregularly lobed or toothed margin.
The rosettes bolt to form very coarse, often tall stems. The whole plant is covered with long,
sticky hairs that give off a foul smelling substance. Black henbane is a highly poisonous
weed, but fortunately, the strong, unpleasant scent deters grazing animals.

Mature

Highly unusual, bell-shaped flowers are formed in crowded, one-sided spikes near the
top of the plant. The petals have a conspicuous network of purple veins on a yellowish
background and once seen, they are never forgotten. Each flower forms a light brown
capsule full of small, kidney-shaped seeds. At full maturity, the capsules open at the top
by a lid. They greatly resemble the shell of a peanut both in shape and texture.

Key features

Large irregularly lobed leaves; long, foul-smelling, sticky hairs; purple-veined yellowish
flowers in one-sided spikes

Life Cycle

annual winter annual biennial creeping perennial simple perennial '

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation 4^

roadsides ^

forage crops, hay fields

turf

waste areas 4^^

130

Juvenile: rosette

Mature

131

Black Medick

Medkago lupulina

Family

Pea Fabaceae

Seedling

Cotyledons are oval and stalldess. The first true leaf is simple, long-stalked and oval. The
second leaf and all remaining leaves are compound with three small leaflets.

Juvenile

Black medick is prostrate with several to many wiry stems branching out from the base to
form a wide, spreading mat. Both the leaves and stems are usually hairy. The trifoliolate
leaves are alternate with two sharply-pointed stipules at the base. Each leaflet has shallow
teeth on the upper margin and a pointed tip. The middle leaflet has a definite stalk while the
other two are sessile.

Mature

Flowers are very small, yellow and pea-like. They occur in dense, head-like racemes near
the ends of the branches. The fruits are small, kidney-shaped seedpods that are black at
maturity. Each seedpod contains a single yellow to olive-green seed.

Key features

Prostrate growth habit; trifoliolate leaf with stalked, central leaflet; small, yellow pea-like
flowers

132

133

Common Groundsel

Senecio vulgaris

Family

Sunflower Asteraceae

Seedling

Cotyledons are oblong with a grooved stalk.

The first true leaves are oval with upward-
pointing teeth along the margin. The petioles
are also grooved, and the underside of the blades is
sometimes pinkish.

Juvenile

Common groundsel forms a basal rosette of leaves that are typically lobed with a toothed
margin. They have a slightly fleshy texture and are either smooth or sparingly hairy. The
leaves have a prominent midrib underneath. Short, erect stems are produced that are
branched and somewhat fleshy. The upper leaves are sessile and have irregularly lohed and
toothed margins.

Mature

Small, cylindrical heads are in clusters at the ends of stems and branches. Each head has
yellow disk flowers barely visible above the surrounding long, black-tipped, involucral
bracts. A narrow tan-colored seed covered with short white hairs is produced by each
flower. The seeds have a conspicuous white pappus.

% of fields
where found

1-4

5-15

16-50

50-1-

■ > ss

not

surveyed

Key features

Somewhat fleshy, lobed leaves; short, somewhat fleshy stems; black-tipped involucral bracts
on the heads

134

Mature

135

Common Mullein

Verbascum thapsus

Family

Snapdragon Scrophulariaceae

Seedling

The cotyledons are ovate with a short stalk and tiny hairs. The first true leaves are oval,
petioled and wooly. Common mullein is found on roadsides and pastures. It usually grows
in sandy or gravelly soils. Seedlings are not commonly seen.

Juvenile

Common mullein is a tap-rooted biennial with a large rosette in the first year. The rosette is
made up of large, whitish-green, wooly leaves that are narrower near the base.

Mature

The second-year flowering stem is wooly, tall and usually unbranched. The white-wooly
leaves hug the stem, giving the stem a winged appearance. The yellow, saucer-shaped
flowers are five-lobed and arranged in a dense, wooly, spike-like raceme at the top of the
stem. Each flower develops into a spherical capsule with two compartments filled with
many seeds. Each seed is six-sided, light to dark brown and has a deeply grooved surface.
The dead flower stalks may remain standing for one or two years.

Key features

Large, white-wooly leaves; second year stem has winged appearance; yellow flowers densely
produced in a thick, wooly, spike-like raceme

136

137

Dandelion

Taraxacum officinale

Family

Sunflower Asteraceae

Seedling

A dandelion seedling has smooth, oval
cotyledons. The first true leaves are oval with
sparse, irregular toothing on the margins.

Juvenile

Dandelion has a deep, penetrating tap root that may be
branched. The leaves are in a basal rosette throughout the life cycle, and there is
no elongated, leafy stem. Margins of dandelion leaves are irregularly lobed and toothed, a
feature that varies considerably from plant to plant. Young dandelions can be distinguished
from perennial and annual sow-thistles by the lack of weak prickles on the margins. The leaf
surface may be smooth or sparsely hairy. The entire plant is filled with a white, sticky juice.

Mature

Solitary flower heads are produced at the top of hollow, leafless stalks. The ray florets are
bright yellow and showy. Involucral bracts around each head are green, linear and in two
whorls. The outer whorl has shorter bracts that are bent baclcwards. The seed is yellowish-
brown, long and slender with a long beak and a pappus for wind dispersal. Dandelions are
traditionally a weed of lawns and turf but are becoming a problem in reduced tillage
systems.

% of fields
where found

Key features

Hollow, leafless flower stalks with bright yellow flower heads; sticky, white latex throughout
plant; leaves all basal

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation -

roadsides

forage crops, hay fields <J^/^

turf

waste areas

138

Seediini

Mature

Infestation

Juvenile

Key feature: seed heads on leafless stalks

139

Family

Mustard Brassicaceae

Seedling

Cotyledons are oval with a small
indentation at the tip. The first true leaves
have simple, white hairs and wavy to slightly-
toothed margins.

Juvenile

Dog Mustard

Erucastrum gallkum

Dog mustard forms a rosette with somewhat hairy, oblong leaves. The leaves are
deeply divided into coarse lobes with margins that may be wavy or irregularly-toothed.

The basal leaves resemble the lower leaves of tumble mustard. Stems are erect and may
be much-branched. The lower stems are covered with short, stiff, downward-pointing hairs.

Mature

Flowers are produced in elongated racemes at the top of the plant. Each flower has four
pale yellow petals. The seedpods are long and narrow, four-sided and have a short beak.
Dog mustard is the only weedy mustard that has flowers and seedpods originating from
the axils of upper stem leaves. Oval, reddish-brown seeds are produced in a single row
within each half of the seedpod.

Key features

Pinnately-divided leaves with coarse lobes; downward-pointing hairs on the lower stems;
flowers and seedpods in the axils of upper leaves

% of fields
where found
0

1-4

5-15

16-50

50-1-

not

surveyed

140

141

Early Yellow Locoweed

Oxytropis sericea

Family

Pea Fabaceae

Seedling

Early yellow locoweed has oval cotyledons and compound, silky-haired true leaves. The
first true leaf has one leaflet only, but the third true leaf will usually have three leaflets. The
leaves have long petioles with hairy stipules at the base. Growing on sandy, eroded pastures
and roadsides, the seedlings are seldom noticed.

Juvenile

Early yellow locoweed has a thick tap root. There may be one or more basal rosettes in
a clump, all coming from the branched, woody stem below ground. The leaflets are
covered with soft, silky hairs giving the leaves a whitish-green apprearance. There are
11 to 17 leaflets per leaf, arranged oppositely or nearly so. The stipules at the base of the
leaves are also hairy. The plant is poisonous, causing erratic behaviour and even death in
livestock.

Mature

Blooming early in May, the lemon-yellow or whitish-yellow flowers are in racemes at the
top of leafless flower stalks. The “keel” of the pea-type flower has a prominent protrusion
or “beak.” The calyx has both white and dark-colored hairs. Pods are leathery, covered with
hair and contain kidney-shaped seeds.

Key features

Basal, whitish-green, hairy leaves with 11 to 17 leaflets; early May bloomer; pale to lemon-
yellow flowers with a prominent beak on the “keel”

Similar species

It has not been clearly established which of the numerous related locoweed species are
poisonous.

142

Mature

Infestation

143

Flixweed

Descurainia sophia

Other names

Tansy mustard

Family

Mustard Brassicaceae

Seedling

Unlike many mustard weeds, flixweed has
narrow, stalked cotyledons. The first true
leaves are usually three-lobed, hairy and
opposite. It is very easy to confuse flixweed with
scentless chamomile at the seedling stage. Scentless
chamomile has rounder, sessile cotyledons and smooth,
five-lobed first true leaves.

usually

Juvenile

Flixweed produces a basal rosette with greyish-green leaves that are finely divided. Stems
are erect and often much-branched. The upper leaves are similar to, but much smaller than
the rosette leaves. Both the stems and leaves are covered with star-shaped hairs.

Mature

Tiny, four-petalled, yellow flowers are produced in racemes at the tops of the stems. Long,
narrow seedpods are formed on short stalks. Each seedpod contains two rows of minute,
orange-colored seeds. Flixweed can be distinguished from the two related tansy mustard
species by the seedpods. They are shorter, wider and longer-stalked in the tansy mustards
than in flixweed.

% of fields
where found
0

1-4

m 16-50
50-t
not

surveyed

Key features

Finely divided leaves; greyish-green color; narrow, short-stalked seedpods

Similar species

Green tansy mustard Descurainia pinnata] grey tansy mustard Descurainia richardsonii

divided leaves

145

Goat’s-beard

Tragopogon dubius

Other names

Western salsify, Johnny-go-to-bed-at-noon

Family

Sunflower Asteraceae

Seedling

Both cotyledons and true leaves are long and linear in shape. Seedling leaves are sessile
with an entire margin.

Juvenile

Goat’s-beard has a deep, thick tap root and leaves that are long, linear and clasping at the
base. Very young leaves are covered with soft, downy hair. Older leaves almost appear grass-
like, but with a more smooth and fleshy texture. Stems are smooth, hollow and contain a
millcy juice. They are usually tall and frequently have dead leaves around the base in the
second year.

Mature

The heads of goat’s-beard are dandelion-like, but much larger and more flat-topped. They
are produced singly at the ends of stems and branches and usually face toward the morning
sun. The heads will turn to follow the sun’s path, but by afternoon, they are completely
closed up. The stems directly below the heads are thickened, which is a key way to
distinguish this weed from other species of goat’s-beard. The ray flowers are a pale lemon
yellow and are enclosed by long, narrow, involucral bracts. The outer flowers tend to open
first so that those in the center may, at first glance, appear to he disks, although they are
not. When seeds are produced, the heads are transformed into large, white, fluffy spheres.
Each seed is narrow and ribbed with a long beak attached to an umbrella-like, feathery
pappus.

Key features

Narrow, grass-like leaves; milky sap; large, white, fluffy seed heads

Life Cycle

annual winter annual biennial

creeping perennial simple perennial

Habitat

conventional tillage rangeland ^

reduced tillage irrigation

forage crops, hay fields turf

wetland
roadsides
waste areas

146

Flower: head

Juvenile

Mature

147

Golden-bean

Thermopsis rhombifolia

Other names

Buffalo-bean

Family

Pea Fabaceae

Seedling

Seedlings are not commonly seen.

Juvenile

Golden-bean is usually found in large patches formed by stout, creeping rootstocks. Stems
are erect, angled and smooth with upper branching. The leaves are alternate and trifoliolate
with two large, ovate stipules at the stem node. The leaflets may have flattened, silky hairs
or be almost hairless.

Mature

Golden-bean is very common and one of the earliest bloomers on the prairies. It is seen in
early May in rangelands and along roadsides. The pea-type flowers are bright, golden-yellow
in short racemes. Each flower develops into a flattened, curved pod with several seeds. The
pods, seeds and flowers of golden-bean have been reported to cause sickness in children,
and the species is considered toxic to livestock.

Key features

Found in patches; bright, golden-yellow flowers blooming in early May; curved seedpods

Juvenile

Gumweed

Grindelia squarrosa

Other names

Curlycup gumweed

Family

Sunflower Asteraceae

Seedling

Seedlings are not commonly seen.

Juvenile

Gumweed is a biennial or short-lived perennial with erect, freely-branching stems. They are
hairless and frequently purple-tinged. The leaves are narrow with entire to toothed margins.
The lower leaves are stalked while the upper are sessile and clasping. The leaves are hairless
but covered with small glands that make the surface appear spotted. The entire plant is
bitter-tasting and avoided by livestock.

Mature

The heads are small, daisy-like and occur in flattened clusters at the ends of stems and
branches. Each head has bright yellow ray and disk flowers surrounded by narrow bracts
with the tips curled baclcwards. The bracts are covered with a resinous “gummy” substance
that makes them extremely sticky to the touch. The seeds of gumweed are cream-colored,
ribbed and lack a noticeable pappus.

Key features

Purple-tinged stems; glandular, spotted leaves; sticky-gummy bracts with a curled tip

150

Flower; head

Mature

151

Leafy Spurge

Euphorbia esula

Family

Spurge Euphorbiaceae

Seedling

Cotyledons are linear in shape, pale green and veiny underneath. The seedling stem often
has a few buds just above the soil surface. The first two leaves that develop appear to be
opposite. Subsequent leaves are alternate, spiraling around the stem.

Juvenile

Stems are erect and hairless with sessile leaves that can be quite densely crowded. The
leaves have entire margins and are linear to lanceolate. All parts of the plant contain a
white, sticky latex. Although leafy spurge does produce viable seed, propagation and spread
of the plant is mainly by extensive vertical and horizontal roots with buds that can produce
new shoots. The vertical part of the root system can extend very deeply into the soil profile.
Leafy spurge is poisonous to most livestock, but not to sheep.

Mature

Leafy bracts are at the base of the flowering clusters located at the top of the stem and
upper branches. Flowers lack petals and are found in groups of several male flowers located
near one female. The pair of greenish-yellow bracts under each grouping of flowers are
almost round with pointy tips. The seed capsule produced from each female flower has
three compartments, each with one seed. Capsules explode at maturity, ejecting the seed a
few metres from the plant. Seed color varies from yellow to grey to brown. There is also a
distinct line on one side of the seed and a yellowish bump near the base.

Key features

White latex in all parts of the plant; deep and spreading roots with buds; greenish-yellow
bracts underneath the flower groupings

152

Juvenile

Flower: dusters

Mature

153

Narrow-leaved Hawk’s-

beard

Crepis tectorum

Family

Sunflower Asteraceae

Seedling

Cotyledons are oval in shape with short
stalks. The first true leaves are more elongated
than the cotyledons and have prominent petioles.

They often have a few distinct, downward-pointing
teeth on the margins. Narrow-leaved hawk’s-beard may be
difficult to distinguish from dandelion at the seedling stage.

Juvenile

Narrow-leaved hawk’s-beard forms a basal rosette, often in late summer or fall. The rosette
leaves are narrow, but have variable margins ranging from sparsely-toothed to deeply lobed.
Identification of this weed at the rosette stage is critical since the winter annual form is
rapidly increasing across the prairies. Stems are erect and usually branched. They may be
smooth or hairy and exude a millcy juice when broken. The leaves on the upper stems are
narrow and entire. They are sessile and sometimes also have pointed lobes that clasp the
stem.

Mature

The bright yellow ray flowers are in small dandelion-like heads in clusters at the top of
branches. The involucral bracts surrounding the receptacle are in several rows. The outer
bracts are much shorter than the inner bracts. Each flower produces a dark purple seed with
ten prominent ribs. The seeds are wind-dispersed with the aid of a hair-like pappus.

% of fields
where found
0

■1 B-15
■n 16-50
50+

not

surveyed

Key features

Winter annual habit; narrow stem leaves; milky juice in stem

Life Cycle

annual winter annual biennial creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

./T

forage crops, hay fields

turf

waste areas

154

JllVGnilB! rosette

Infestation

Mature

155

Orange Hawkweed

Hieracium aurantiacum

Other names

Devil’s paint-brush

Family

Sunflower Asteraceae

Seedling

Cotyledons are round to oval in shape. The first true leaves are hairy with entire to finely-
toothed margins.

Juvenile

Like strawberry, orange hawkweed has leafy runners that can root and produce new plants.
Its leaves are mostly in a basal rosette. They are rounded at the tip and then narrow at the
base into winged petioles. Both surfaces of the leaves are usually covered with stiff hairs.
Stems are hairy, nearly leafless and contain a bitter, milky sap.

Mature

Dandelion-like heads are located in flat-topped clusters at the tops of stems. The ray flowers
are orange-red, making this weed very easy to identify when mature. There are several other
related hawkweed species in Canada, but all have yellow flowers. The involucral bracts
surrounding the flowers appear blackish due to the gland-tipped hairs. Each flower
produces one purplish-black, narrow, ribbed seed with a hair-like pappus.

Key features

Leafy runners; leafless, hairy stems; clusters of orange-red dandelion-like heads

156

Juvenile; basal rosette

Infestation

157

Pasture Sage

Artemisia frigida

Other names

Fringed sagebrush

Family

Sunflower Asteraceae

Seedling

The seedling has tiny oval cotyledons and hairy, silvery-grey leaves with slightly lobed
margins.

Juvenile

Plants are low to the ground, with a woody base. Stems branch from the base of the plant,
producing a mat-like appearance. The leaves are hairy, silvery-grey, finely divided and have
a sage aroma. The lower leaves are petioled while the upper leaves are sessile, alternate and
less finely divided. Pasture sage is an indicator of overgrazing, and the weed is quite
drought tolerant.

Mature

Many small, yellowish flower heads are found on short flower stalks from upper leaf axils.
The numerous, nodding heads have fertile florets in the centre and hairy bracts around the
outside. Tiny, smooth, grey-brown seeds are produced in large amounts. There is no pappus.

Key features

Short statured plant with sage odor; silvery-grey, hairy leaves with finely divided margins;
numerous, small, nodding heads

158

Mature

Juvenile

Infestation

159

Perennial Sow-thistle

Sonchus arvensis

Family

Sunflower Asteraceae

Seedling

Cotyledons are oval with slight indents
at the tip. The first true leaves are
spatulate with soft prickles along the
margins. Seedlings are almost impossible
to distinguish from other species of sow-
thistle.

Juvenile

Perennial sow-thistle has extensive, horizontal, deep,
creeping roots. These roots are light-colored, fleshy and
easily broken. Each piece of broken root containing a bud can produce
a new plant and potentially start a new infestation. Juvenile plants form rosettes of basal
leaves that vary in shape from shallow to deeply lobed. The basal leaves may resemble
dandelion but instead have winged stalks and prickles on the margin. Often, discrete
patches of rosettes are found in an area, suggesting the perennial nature of this weed. Plants
have erect stems that are hollow and contain a milky sap. They are smooth at the base but
often have orange hairs near the top. Upper leaves are typically more deeply lobed than
basal leaves. Although they also clasp the stem, the lobes at the base of the leaf are smaller
than in the annual sow-thistle species.

Mature

Heads are found in clusters at the ends of branches. Each head is dandelion-like with bright
yellow, ray flowers. The involucral bracts surrounding the heads are covered with dense,
oranged-colored hair. A related perennial sow-thistle species, Sonchus uliginosus, is similar
in appearance but completely smooth on the upper stems and bracts. The heads of
perennial sow-thistle are larger and more flask-shaped than those of the annual species.
Seeds are brown with both lengthwise and crosswise ribs giving them a wrinkled look. They
have a pappus and are easily moved by wind.

Key features

Fleshy, white, underground creeping roots; lobed leaves with a prickly margin; upper stems
and bracts with orange hair

Similar species

Perennial sow-thistle Sonchus uliginosus

Life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

% of fields
where found

5-15

■1

16-50

50 +

■ .

not

surveyed

Seedlini

Mature

161

Matricaria matricarioides

Family

Sunflower Asteraceae

Seedling

Cotyledons are oblong and stalldess. The
first true leaves are long and narrow with
scattered lobes along the margin.

Juvenile

Juvenile plants have leaves that are finely-divided, smooth and
slightly fleshy to the touch. Pineappleweed greatly resembles scentless chamomile
at this stage, but can be easily distinguished by the distinct pineapple odor when the leaves
are crushed. Its stems are short, smooth and much-branched.

Mature

Ovate heads comprised of tiny, yellowish-green disk flowers are produced at the tops
of branches. They lack the white, ray flowers associated with scentless chamomile and
resemble minature pineapples instead of daisies. Each flower produces a single, tiny, olive-
to-brown seed with no obvious pappus.

Key features

Finely-divided leaves with pineapple odor; short, smooth stems; pineapple-shaped heads

%oHieids
where found

162

163

Polish Canola

Brassica rapa

Other names

Turnip rape

Family

Mustard Brassicaceae

Seedling

Polish canola cotyledons are broad, kidney-shaped and wrinkled underneath. The leaves
are green and hairy, lacking the waxiness and bluish-green tinge of Argentine canola. The
leaves are alternate and petioled with irregularly and shallowly lobed margins. Although the
base of the stem is usually hairy, this feature varies with cultivar. Polish canola is difficult to
distinguish from wild mustard at the seedling and early juvenile stages. The base of the stem
of wild mustard is usually more bristly-hairy than Polish canola. In addition, wild mustard
stem nodes may develop purple coloration, even at a young age.

Juvenile

The basal rosette of Polish canola has green, hairy, petioled leaves. Typically, the rosette is
smaller than the rosette of Argentine canola. Once the plant bolts, Polish canola is more
branched than Argentine canola and may have up to 20 branches. The stem leaves are
alternate, entire, sessile and totally clasp the stem with rounded basal lobes. In contrast,
wild mustard stem leaves are coarsely toothed and sessile, but not clasping. Also, wild
mustard stem nodes develop purple blotches while the nodes of Polish canola do not have
this coloration.

Mature

Flowers are produced in terminal and axillary racemes. Each flower has four deep yellow
petals, which are smaller than those of Argentine canola. Unopened flower buds are located
below the opened flowers on the raceme. Each flower develops into a seedpod that is
shorter than an Argentine canola pod. The beak at the top of the pod is longer than the
beak on Argentine canola pods, and Polish canola seedpods have less tendency to shatter.
Mature seeds of Polish canola are mixtures of brown and yellow seeds, which are smaller
than Argentine canola seeds.

Key features

Green, hairy leaves; upper stem leaves fully clasping the stem; unopened flower buds below
the opened flowers

164

165

Prairie Sunflower

Helianthus petiolaris

Family

Sunflower Asteraceae

Seedling

Seedlings have oblong cotyledons and oppositely arranged first true leaves. Leaves are
petioled and lanceolate to ovate in shape. This plant is often not noticed until it blooms in
its usual habitat along roadsides and edges of fields. Prairie sunflower is more frequently
found on sandy soils while the related species, annual sunflower, is more typical of heavier
soils.

Juvenile

Prairie sunflower is fibrous tap rooted with erect stems covered with short hairs, flattened
to the surface. In contrast, stems of annual sunflower are rough and bristly-hairy to the
touch. Leaf margins of prairie sunflower are entire or slightly wavy while those of annual
sunflower are distinctly toothed. Prairie sunflower leaves are lanceolate to ovate and
narrower at the base. Annual sunflower leaves are broadly ovate and often cordate at the
base. Leaves of both species are mostly alternate, but lower ones may be opposite.

Mature

Flower heads of prairie sunflower are smaller in diameter than those of annual sunflower.
Both species have bright yellow ray flowers around the perimeter. The central disk flowers
are purplish to brown and flattened. The involucral bracts around the receptacle of prairie
sunflower are lanceolate, gradually tapering to the tip and covered with short hairs. The
disk bracts on the receptacle are white-bearded at the tip. Involucral bracts of annual
sunflower are long-hairy on the surface with long marginal hairs. Disk bracts are hairy but
lack the white-bearded tip.

Grows in sandy or gravelly locations; narrowly ovate blade tapering to the base with entire
to wavy margins; disk bracts white-bearded and long marginal hairs lacking on involucral
bracts

Similar species

Annual sunflower Helianthus annuus

Life Cycle

annual winter annual biennial creeping pemal simple perenniak.

Habitat

conventional tillage

rangeland

wetland

reduced tillage ^

irrigation

roadsides

forage crops, hay fields

turf

waste areas ^

166

Flower: head

167

Prickly Lettuce

Lactuca scariola

Other names

Compass plant

Family

Sunflower Asteraceae

Seedling

Cotyledons are oval and short-stalked. The first true leaves are shallowly lobed with soft
prickles along the margin.

Juvenile

Pricldy lettuce forms erect, mostly smooth, whitish-green stems that contain a milky juice.
The lower leaves are deeply lobed, and the lobes tend to point backwards. The upper margin
on each lobe is spiny-toothed while the lower margin is nearly entire. Upper leaves are
usually less lobed and more pointed at the base than lower leaves. Unfortunately, the lobing
on the leaves varies greatly from plant to plant. However, there are two very unusual
features about the leaves of prickly lettuce to aid in identification. Firstly, most leaves have
a single row of sharp prickles on the midrib on the underside. Secondly, the leaves are
usually twisted at the base so that the blades are oriented vertically. Often, the leaf tips are
aligned to point north-south, giving this weed the reputation of being a “compass plant.”

Mature

The heads are extremely small and occur in much-branched clusters at the top of the plant.
Each head has five to twelve yellow ray flowers that turn blue when the plant is dried. A
related species, Lactuca pulchella, is very similar to prickly lettuce except that its flowers
are always blue, and it is a creeping perennial. Each flower of prickly lettuce produces a
narrowly oval, ribbed seed with a long beak. The seeds have a white pappus and are readily
wind-dispersed.

Key features

Sharp prickles on leaf midribs; vertically-aligned leaves; much-branched cluster of yellow
heads

Similar species

Blue lettuce Lactuca pulchella

Habitat

conventional tillage

rangeland 4^

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

168

Purslane

Portulaca oleracea

Other names

Wild portulaca

Family

Purslane Portulacaceae

Seedling

The cotyledons are linear on short stalks. True leaves are succulent, teardrop-shaped and
often reddish-green.

Juvenile

Purslane has a thick tap root and a prostrate growth habit. The smooth, fleshy stems form
large circular mats on the soil surface. The leaves are sessile, succulent and alternately
arranged, sometimes closely alternate. The fleshy, veinless leaves of purslane distinguish
it clearly from other prostrate plants. Uprooted or broken-stemmed plants can re-establish
roots, making purslane troublesome in gardens and row crops.

Mature

Flowers are yellow and usually have five petals. They are solitary or in small, axillary or
terminal clusters and open only on bright, sunny mornings. Each flower develops into a
spherical capsule that opens by a lid on top. The numerous seeds are black, shiny and
bumpy. They are almost kidney-shaped with a white scar at one end.

Key features

Prostrate mats on soil surface; succulent leaves without veins; stems fleshy and often
reddish

170

Seedlini

171

Rough Cinquefoil

Potentilla norvegica

Family

Rose Rosaceae

Seedling

Cotyledons are round. The first true leaves
are unifoliolate with only a few teeth on the
margin.

Juvenile

Rough cinquefoil has erect to spreading stems that are usually
branched at the top. They are covered with stiff, often reddish hairs. Leaves are
trifoliolate with three oblong leaflets and a pair of leaf-like stipules at the base. The lower
leaves are petioled while the upper leaves are sessile. This weed is sometimes mistaken for
strawberry at the juvenile stage. The leaves on rough cinquefoil have coarse, forward-
pointing teeth on the margin surrounding each leaflet while strawberry leaflets are usually
only toothed around the tip.

Mature

Flowers are found in clusters on short stalks emerging from leaf and branch axils. Each
flower has five, pale yellow petals that are about the same size or even shorter than the
green sepals. At first glance, it appears that there are ten sepals, but five of them are actually
bracts. The flowers each produce a group of tiny, roughly oval-shaped seeds. Each seed is
yellowish-brown with prominent branching ribs.

% of fields
where found

Key features

Hairy, often reddish stems; trifoliolate leaves with toothed margins and stipules; yellow
flowers with petals and sepals about the same length

172

Flower

173

Spiny Annual Sow-thistle

Sonchus asper

Other names

Prickly annual sow-thistle

Family

Sunflower Asteraceae

Cotyledons are fleshy and round to oval. The true leaves are oval to spoon-shaped and
petioled. Margins of the true leaves have soft prickles. The seedlings of the two annual and
two perennial sow-thistle species commonly found on the prairies are almost impossible to
distinguish from each other.

Juvenile

Spiny annual sow-thistle is a tap rooted species with a white, sticky juice throughout the
plant. The tap root distinguishes it from perennial sow-thistle, which has extensive,
creeping roots. The rosette of spiny annual sow-thistle has glossy leaves with undulating,
spiny-toothed margins. The stem is erect and branched at the top. Mid and upper alternate
leaves clasp the stem with prominent, rounded, basal lobes. Spines on the leaf margins are
unpleasant to touch. Leaves of annual sow-thistle, Sonchus oleraceus, are not glossy and
have deeply lobed to divided margins. They have a broad, triangular, terminal lobe and are
narrow near the base of the leaf, much like a winged petiole. They clasp the stem with basal,
pointed lobes. Prickles on the leaf margins are weak, sparse and not unpleasant to the
touch. Perennial sow-thistle leaves on the mid-stem have small, rounded, basal lobes but
lack these on uppermost leaves.

Mature

The flower heads of both spiny annual sow-thistle and annual sow-thistle are almost
triangular with a broad base and a narrow top. The heads of both species have pale yellow
ray flowers. Heads of perennial sow-thistle can be distinguished by their much larger size
and much deeper yellow flower color. Each flower of spiny annual sow-thistle produces a
single, flattened brown seed with several lengthwise ribs. Annual sow-thistle seeds are
similar, but have small cross-wrinkles in addition to the lengthwise ribs.

Key features

Tap root; leaves shiny with undulating, spiny-toothed margins and rounded basal lobes;
triangular-shaped heads with pale yellow flowers

Similar species

Annual sow-thistle Sonchus oleraceus

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation ^

roadsides

forage crops, hay fields

turf ^

waste areas

Life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

174

175

Tall Buttercup

Ranunculus acris
Family

Buttercup Ranunculaceae

Seedling

Cotyledons are round to oval and long-stalked. The true leaves have long petioles and
blades with three to five rounded lobes.

Juvenile

Tall buttercup has long, erect stems emerging from a short, but thick, rootstock. They have
a hairy surface and are often branched near the top of the plant. The basal and lower leaves
have long petioles and are softly hairy on both surfaces. The blade is palmately divided into
five elongated lobes, each further divided into narrow, toothed segments. The upper leaves
are small, nearly stalkless and usually three-lobed. Tall buttercup is highly unpalatable due
to the presence of a bitter juice throughout the plant. If grazed, the juice can cause
blistering and inflammation of the mouth and digestive system.

Mature

Bright yellow flowers with five rounded petals are located on long stalks at the top of the
plant. Each flower produces a cluster of beige-yellow, egg-shaped, flattened seeds with a
short, hooked tip.

Key features

Long, erect, hairy stems; hairy, palmately-divided leaves; bright yellow flowers on long
stalks

176

Mature

Infestation

177

Tanacetum vulgar e

Other names

Common tansy

Family

Sunflower Asteraceae

Seedling

The cotyledons and first true leaves are oval. The early leaves are petioled, hairy and have
a slightly lobed margin. As leaves are produced, each one has progressively more lobes than
the previous ones. Later, leaves tend to have a smooth surface.

Tansy has short rhizomes and tends to form large clumps of smooth, erect stems. The lower
leaves are long-stalked and deeply cut into segments, which are, in turn, divided. They
appear almost fern-like. Stem leaves are numerous, sessile and smaller than the basal
leaves. Both types of leaves are covered with small glands and the. entire plant is aromatic.
Tansy is poisonous to livestock, but is usually avoided because of the strong odor.

Heads are in dense, round to flat-topped clusters. Each head is button-like and composed of
many tightly packed, yellow disk flowers. The seeds are grey-tan, ribbed and lack an obvious

Juvenile

Mature

pappus.

Key features

Short rhizomes; fern-like, aromatic leaves; yellow, button-like heads in clusters

annual

winter annual

biennial creeping perennial simple perennial

conventional tillage
reduced tillage
forage crops, hay fields

wetland

irrigation

turf

178

Juvenile

Mature

179

Tumble Mustard

Sisymbrium altissimum

Family

Mustard Bmssicaceae

Seedling

The cotyledons are stalked and oval with a slight notch at the tip. The first few true leaves
are hairy and petioled with slightly lobed margins. Subsequent leaves have deeper lobing.

Juvenile

The basal rosette has large, petioled leaves covered with white, unbranched hairs. Margins
are deeply lobed or divided to the midrib. The stem has white hairs at the base or can be
hairless. The upper stem leaves are finely divided into narrow, threadlike segments that may
have a few scattered teeth. The lower basal leaves of the rosette usually die before flowering
occurs.

Mature

Pale yellow flowers with four petals are produced in short racemes at the ends of branches.
The pods are very long, thin and smooth with no obvious beak at the tip. The small seeds
are oblong, varying in color from yellow to reddish-yellow to olive-green. The mature stem
becomes brittle and breaks at the base. The plant tumbles along the ground to distribute
seed.

Key features

Lower leaves divided and upper leaves finely divided; pale yellow flowers; narrow pod that
is much longer than other members of the Brassicaceae

Seedlini

181

€

Wild Mustard

Brassica kaber

Family

Mustard Bmssicaceae

Seedling

The broad, kidney-shaped cotyledons are
similar to both Polish and Argentine canola.
The first true leaves are petioled, slightly lobed
and hairy.

Juvenile

The stem is branched with bristly downward-pointing hair near the base and
becomes less hairy or hairless near the top. Usually, the bases of Polish canola stems are less
hairy. In the rosette stage, the stalked lower leaves of the plant have several deep lobes near
the base of the blade and a large terminal lobe. There are sparse hairs, especially on the
veins on the undersurface of the leaf. Upper leaves are sessile and coarsely toothed, but not
clasping. Stem nodes and the bases of branches develop purple blotches, a feature that is
useful to distinguish wild mustard from Polish canola, which does not develop this
coloration.

Mature

The flowering racemes have bright yellow flowers with four petals. Each flower develops
into a cylindrical, ribbed pod with a flattened beak that is about one third the length of the
pod itself. There is often one seed at the base of the beak. The stalk at the base of the pod is
very short and almost as thick as the pod. Seeds are spherical, brown to black and minutely
netted under magnification.

% of fields
where found
0

WM 5-15

not

surveyed

Key features

Downward-pointing bristly hairs on lower stem; upper stem leaves coarsely toothed and
sessile, but not clasping; purple blotches at stem nodes

(

Seedlin

183

Wild Radish

Raphanus raphanistrum
Family

Mustard Brassicaceae

Seedling

Cotyledons are broad and kidney-shaped. The first true leaves usually have two small lobes
at the base and slightly wavy margins. Wild radish is very difficult to distinguish from wild
mustard at the seedling stage.

Juvenile

The basal rosette leaves are deeply-divided with a prominent, terminal lobe. They are
frequently covered with a few, short, stiff hairs and are rough to the touch. Stems are erect
and often freely-branched. They are covered with coarse, short hair, especially at the base.
The upper stem leaves are narrower than the rosette leaves and usually have entire margins.

Mature

Flowers are produced in racemes at the ends of stems and branches. Most flowers have four
pale yellow petals, although they may occasionally be white or even purple. Typically, the
petals are conspicuously veined. Seedpods are long and narrow with a slender, pointed beak
at the tip. They have distinctive constrictions between the seeds and break apart into
segments at maturity. Each segment contains one oval, reddish-brown seed covered with
fine net veins. Mature wild radish plants are easily confused with wild mustard. However,
wild mustard flowers are smaller, a deeper yellow color and they lack the conspicuous veins
on the petals. The seedpods of wild mustard also do not exhibit constrictions between the
seeds.

Key features

Deeply-divided basal leaves; conspicuously-veined petals; constricted seedpods

184

imenWe: rosette

Mature

Infestation

185

Wood Whitlow-grass

Draba nemorosa

Other names

Yellow whitlow-grass

Family

Mustard Brassicaceae

Seedling

The seedling is very small and can easily be overlooked. It has ovate, sessile leaves.

Juvenile

The basal rosette has ovate leaves with two, three and four-pronged hairs. The leaf
margins are finely toothed. Its tiny rosettes are similar in size to pygmyflower, and both
species are often found in the same habitat. Wood whitlow-grass can be distinguished from
pygmyflower by the branching hairs on the leaves. Pygmyflower leaves have minute, simple
hairs or are hairless. Stems of wood whitlow-grass have simple and forked hairs.

Mature

This plant is seen very early in stubble fields, usually after it has bolted and flowered.
Flower racemes have widely spaced flowers on long stalks. Each tiny yellow flower has
four petals that are slightly notched at the tip. Each flower develops into a flattened,
elliptical pod that points upward. The stalk on each pod is as long or longer than the pod
itself. Flowering and seed set occur very early in spring.

Key features

Tiny rosette and short stature of mature plant; early bloom and seed set; stalk of each
upward-pointing pod as long as or longer than the pod itself

Life Cycle I

annual

winter annual

biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland 0^

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

186

Infestation

Juvenile! rosette

Mature

flowering racenn

187

Yellow Nut Sedge

Cyperus esculentus

Family

Sedge Cyperaceae

Seedling

Seedlings are seldom found in the field.

Juvenile

Yellow nut sedge is a creeping perennial weed with fibrous roots and long, light brown to
white wiry rhizomes. The rhizomes may or may not end in dark brown, nut-like tubers.

Both the tubers, when present, and rhizomes allow this weed to spread vigorously
underground. Tall, unbranched, smooth stems are produced that are distinctly triangular in
cross-section. The long, narrow leaves appear grass-like and are flat or somewhat folded.

The leaves emerge from all three sides of the stem and occur mostly towards the base of the
plant. Yellow nut sedge is considered one of the worst weeds in the world and has recently
started to appear in moist areas in the eastern prairies.

Mature

Small, yellowish-brown flowers are grouped into flattened spikelets located in umbrella-like
clusters at the tops of stems. There are usually three to four long, thin leaves located below
each inflorescence. The seeds of yellow nut sedge are long, elliptical in shape and
conspicuously three-sided.

Key features

Long, wiry rhizomes, often with brown tubers attached; triangular stems with narrow, grass-
like leaves at the base; yellowish-brown flowers in umbrella-like clusters

Life Cycle I

annual

winter annual

biennial creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland ^

reduced tillage

irrigation ^

roadsides

forage crops, hay fields

turf

waste areas

Juvenile

Mature

Yellow Sweet Clover

Melilotus officinalis

Family

Pea Fabaceae

Seedling

Cotyledons are oblong with a round tip. The first true leaf has a single, broadly oval blade
and a long, grooved stalk. Subsequent leaves are all trifoliolate.

Juvenile

This biennial weed produces a large, deep tap root and basal rosette in the first year. The
compound leaves are divided into three, narrowly oval leaflets. Only the terminal leaflet is
stalked. The margins of all leaflets are toothed, almost to the base. Erect, often very tall,
free-branching stems are formed in the second year. They typically have a smooth but
strongly ridged surface. It is difficult to distinguish yellow sweet clover from its close
relative, white sweet clover, until flowers and fruits are produced. Although both species
of sweet clover are weedy in certain areas, they are also commonly grown as forage crops.

Mature

Yellow sweet clover has irregular, pea-like flowers in narrow, elongated racemes. Each
yellow flower produces a small, egg-shaped pod with a wrinkled surface. The pods contain
one or two olive green seeds that are also frequently purple-spotted. As the name suggests,
white sweet clover forms white flowers that are smaller but similar in appearance to yellow
sweet clover. Its pods have a net-veined surface and contain yellow colored seeds.

Key features

Trifoliolate leaves with leaflet margins toothed almost to the base; yellow pea-like flowers in
elongated racemes; small, egg-shaped pods with a wrinkled surface

Similar species

White sweet clover Melilotus alba

Life Cycle I

annual

winter annual

biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland 4^

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields ^

turf

waste areas

Mature

191

Yellow Toadflax

Linaria vulgaris

Other names

Butter-and-eggs, wild snapdragon

Family

Snapdragon Scrophulariaceae

Seedling

Yellow toadflax cotyledons are round with a very prominent rounded bump at the top. The
first few true leaves are oval. Subsequent leaves are narrower and linear. This species is
becoming more prevalent in reduced tillage systems.

Juvenile

Yellow toadflax spreads by extensive creeping roots that form dense patches. The stems are
erect, hairless and branched above. The leaves are alternate, although often crowded on the
stem. The linear leaves are narrowed at both ends. This feature helps to distinguish it from
Dalmatian toadflax, which has lanceolate to broadly ovate leaves that clasp the stem. Before
flowering, yellow toadflax can be distinguished from leafy spurge by breaking the stem.

Leafy spurge has a white milky latex inside while yellow toadflax does not. Yellow toadflax
contains some toxic compounds but is usually avoided by grazing livestock.

Mature

Bright yellow flowers with orange centres are grouped into racemes at the ends of stems and
branches. Each flower is “snapdragon-like” with an upper lip and a lower lip that has a
conspicuous protrusion or “spur” extending downwards. Each flower develops into a seed
capsule that releases many dark brown to black seeds. Each seed is flattened with a circular
wing on the margin for wind distribution.

Key features

Found in patches due to creeping roots; crowded, linear leaves that are narrower at each
end; bright yellow and orange flowers that are “snapdragon-like”

Similar species

Dalmatian toadflax Linaria dalmatica

Life Cycle I

annual

winter annual

biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf ^

waste areas

192

Mature

Flower

Infestation

193

Green

Flowered Sp

ecies

Barley

Hordeum vulgare

Family

Grass Poaceae

Seedling

Leaf blades and sheaths are hairless, although occasional hairs occur on the upper blade of
some varieties. Barley has large white, conspicuous auricles that make it readily identifiable
in the field. The ligule is long, white and membranous. Leaf blades are wide in comparison
to wheat.

Juvenile

Barley occurs as a volunteer weed and can be a vigorous competitor. It has a fibrous root
system, erect stems and often produces many tillers.

Mature

The inflorescence is a spike with either two or six rows of kernels. Two-row spikes are
much thinner and flatter in appearance than six-row spikes. In both two-row and six-row
varieties, there are three spikelets at each rachis node. Only the central spikelet in two-row
types has a floret that develops into a grain or seed. The lateral spikelets are sterile. All
three spikelets in six-row varieties have one floret that develops into one grain. The two tiny
white glumes on the outside of each spikelet are awned, and there is a long awn or beard
extending from the tip of each grain. The beard is either barbed or smooth and is broken off
during threshing. Barley grains are straw-colored and can be hulled or hulless.

Key (eatures

Large, white, claw-like auricles; awned glumes; beard extending from tip of grain either
barbed or smooth

Life Cycle

annual winter annual biennial creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides ^

forage crops, hay fields 4^

turf

waste areas

196

197

Family

Grass Poaceae

Seedling

The leaves of barnyard grass are completely
hairless although the margins of the blade
may be slightly rough. Auricles are absent. It is
the only grass weed on the prairies that has no
ligule, making this an excellent identification feature.

Barnyard Grass

Echinochloa crusgalli

Juvenile

Barnyard grass has fibrous roots and a spreading, horizontal growth habit. Stem nodes in
contact with the soil often form roots. The sheath of each leaf is rather flattened and may
be purplish near the base.

Mature

The inflorescence is a tufted, compact panicle that is often purplish. The branches are
covered with densely-crowded spikelets that are covered with stiff hairs. Only one of the
two florets will develop into a seed. The sterile second floret often has a bristly awn
extending from the tip. The seed is shiny, pale yellow to brown, flattened on one side and
rounded on the other.

Auricles and ligule absent on hairless leaves; horizontal growth habit; bristly-looking
panicles densely crowded with spikelets

% of fields
where found
0

f 14
WM 5-15
1 16-50
50-1-

t not
surveyed

Life Cycle

annual winter annual biennial creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

198

Panicle

199

Broad-leaved Plantain

Plantago major

Family

Plantain Plantaginaceae

Seedling

Cotyledons are oval. The true leaves are
oval and petioled. They emerge one at a time
to form a basal rosette.

Juvenile

The root is short and thick with many tough, lateral roots.

Broad-leaved plantain lacks an above-ground stem, and the leaves remain in a
basal rosette throughout the life cycle. The leaf margins are entire or occasionally toothed.
The oval to ovate leaves have thick petioles that are as long as the leaf blades. The leaves
are prominently ribbed with three to seven main veins and may be smooth or slightly hairy.
This weed is commonly found in lawns.

Mature

Flowers are arranged in narrow, cylindrical spikes at the top of leafless flower stalks.
Depending on plant density, there may be several to several dozen flower stalks per plant.
Broad-leaved plantain flowers and sets seed from spring to late autumn, and its pollen can
cause hay fever. A small individual green flower develops into an egg-shaped capsule that
splits to release numerous seeds. The seeds are dark brown to black and have various,
angular shapes. There are threadlike ridges on the seed surface and a pale scar on one side.

% of fields
where found

Key features

Remains a basal rosette throughout life cycle; oval, prominently ribbed leaves with thick
petioles as long as the blades; leafless flower stalks with green-flowered spikes

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage <y^

irrigation

roadsides

forage crops, hay fields

waste areas

201

Cocklebur

Xanthium strumarium
Family

Sunflower Asteraceae

Seedling

Cotyledons are long and narrow, persisting at the base of the stem, sometimes until
maturity. First true leaves are opposite, petioled and ovate with toothed margins. The
remains of the bur below ground can be used to confirm seedling identification. Seeds and
young seedlings are poisonous to livestock.

Juvenile

Cocklebur is tap rooted with erect, rough-hairy stems that are ridged and have purplish
spots. Leaves have three main veins and are ovate to heart-shaped or triangular. Lower
leaves are opposite; upper leaves are alternately arranged. Leaves and stems are rough
to the touch due to glandular hairs. These hairs can cause a rash in allergic individuals.

Mature

Male and female flower heads are separate, but are on the same plant. They are located
at the ends of the main stem and branches as well as in leaf axils. Male flower heads are
spherical, non-spiny and produce pollen that causes an allergic reaction in some people.
The female flower head is a green, spiny bur containing two flowers. The bur is covered
with spines and has two beak-like spines at the tip. It becomes brown, hard and woody at
maturity. The two seeds inside each bur are oblong, flattened and grey to dark brown, with
one usually larger than the other.

Key features

Rough-hairy leaves and stems; ovate to heart-shaped or triangular leaves with three main
veins; large, spiny burs

Life Cycle I

annual

winter annual

biennial creeping perennial simple perennial

Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides ^

forage crops, hay fields

turf

waste areas

202

203

Brome

Other names

Downy chess, cheat grass

Family

Grass Poaceae

Downy

Bromus tectorum

Seedling

Leaf blades and sheaths of downy hrome are pale green and covered with soft, dense hairs
on both surfaces and margins. Venation is indistinct except for the midrib on the lower
surface. Auricles are absent. The ligule is membranous, approximately 3 mm long and torn
along the top.

Juvenile

The plant tillers to produce a tufted clump. The erect stems are slender and usually hairy,
and the leaf sheaths are closed at the bottom and split at the top. The root system is fibrous,
growing to a depth of about 30 cm. In some areas, downy brome. is considered to be forage.
Smooth brome, the related forage grass, is a perennial with branching rhizomes and smooth
leaves with rough margins. The leaf texture and presence of rhizomes can be used to
distinguish smooth brome from downy brome.

Mature

The panicle has long, drooping branches. It is pale green and becomes tinged with purple
as it matures. Spikelets have hairy, uneven-sized outer glumes and are multi-floreted, each
floret developing into one seed. The seeds are also softly hairy with a short, slender, rough
awn emerging from just below the tip. Immature heads feel soft to the touch. Smooth brome
panicles are not awned and hence, are easily distinguished from downy brome.

Key features

Soft, densely-hairy leaves; drooping, purple panicles; short, slender awns on seeds

Similar species

Smooth brome Bromus inermis

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

204

False Ragweed

Iva xanthifolia

Other names

Burweed, marsh elder

Family

Sunflower Astemceae

Seedling

Cotyledons are oval and stalked. The first true leaves are opposite with variably lobed
margins and a soft, hairy texture.

Juvenile

Stems are erect and much-branched. They are usually smooth, but occasionally hairy at the
top. Leaves are mostly opposite with long, hairy petioles. The lower leaves are often three-
lobed while the upper are broad, almost heart-shaped, with coarse, irregularly-toothed
margins. Both surfaces of the leaves are covered with flattened hairs, giving them a velvety
feel. The long petioles, toothed margins and ovate upper leaves rnay cause confusion with
cocklebur at this stage. However, false ragweed has opposite, velvety leaves while the leaves
on cocklebur are alternate and rough-textured.

Mature

The heads of false ragweed are small, greenish and located in loose, branching clusters at
the top of the plant. Each head has male and female flowers surrounded by five pointed
involucral bracts. The central flowers on the head are male and produce pollen that may
cause hay fever in some people. The marginal flowers are female and each can produce one
seed. Usually five seeds are found in a ring around the male flowers. The seeds are brown to
black, very finely grooved and lack a pappus.

Key features

Velvety, opposite leaves; irregularly-toothed leaf margins; loose clusters of small green
flower heads

206

207

Field Dock

Rumex pseudonatronatus

Family

Buckwheat Polygonaceae

Seedling

Cotyledons are elliptical in shape. The first true leaf is petioled and broadly oval with entire
margins.

Juvenile

Field dock is more abundant on the prairies than curled dock {Rumex crispus), which is
more abundant in Eastern Canada. Western dock {Rumex occidentalis) is a native dock
that is non-weedy but very similar to field dock. Western dock and field dock are extremely
difficult to distinguish.

Field dock has a deep tap root. In the spring, new buds grow from the previous year’s
rosette. Stems are erect with ocreas at the nodes. Leaf arrangement is alternate. The narrow,
lanceolate leaves have wavy-curled margins and taper to the base. Leaves of Western dock
have round basal lobes and taper to the tip. Stems of both dock species are commonly red-
tinged as maturity approaches.

Mature

Both field dock and Western dock have long, narrow, densely-flowered panicles. The stalk of
each flower of field dock is distinctly jointed. Flower stalks of Western dock are unjointed.
Each flower lacks petals but has six sepals in two whorls of three. The inner sepals are
enlarged and form the winged valves of the fruit. These valves are heart-shaped in both
species. The flower stalks of field dock are two to three times longer than the valves.

Western dock flower stalks are about the same length as the valves. Projections called
“tubercles” are absent on the valves of both species, although there may be a slight swelling
on one valve of field dock. Seeds are brown and three-angled.

Key features

Ocreas at stem nodes; stalk of each flower distinctly jointed; heart-shaped valves of fruit
that may have a swelling on one valve

Similar species

Western dock Rumex occidentalis

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage ^

irrigation

roadsides

forage crops, hay fields

turf

waste areas

Field Horsetail

Equisetum arvense

Other names

Scouring rush, pinegrass, mare’s tail

Family

Horsetail Equisetaceae

Seedling

Field horsetail does not form seedlings
because it is not a flowering, seed-
producing plant. Instead of seedlings, stems
are produced from underground rhizomes.
These rhizomes often have attached tubers that
may also break off to start a new plant.

Juvenile

A unique feature of field horsetail is that it has two distinctly different types of stems.

Both types pull apart easily at the nodes. In early spring, the first stems to emerge are
reproductive and are described more fully below. The secondary, vegetative stems are what
most people recognize as field horsetail. They are green, hollow and more slender than
the reproductive stems. Each node on the secondary stems has whorled branches and is
surrounded by a small, toothed sheath. At first glance, field horsetail can be confused with
corn spurry, another weed with a whorled arrangement. However, with closer inspection, it
is easy to see that corn spurry has leaves, not branches, and that its stems are not easily
separable at the nodes. It is also an annual that lacks rhizomes. Field horsetail is poisonous,
particularly to young horses. They usually do not choose to eat it in the field, but may not
be able to avoid it in hay.

Mature

% of fields
where found
0

14
5-15
16-50
50 +
not

surveyed

The reproductive stems that emerge early in spring are white-brown and unbranched. They
are hollow with each node surrounded by a sheath with black teeth. The stems are topped
with a cone-like structure containing spores. Once the spores are released, these stems
wither away, soon to be replaced by the secondary stems.

Key features

Green vegetative stems with whorled branches; brown reproductive stems topped by a
spore-producing cone; both stems hollow with toothed sheaths and easily separable at
the nodes

1 Habitat

conventional tillage <y^

rangeland

wetland

reduced tillage

irrigation

roadsides 4/^^

forage crops, hay fields

turf

waste areas

210

211

Other names

Wild barley

Family

Grass Poaceae

Seedling

The first few greyish-green leaves appear as
thin, vertical wisps. They are covered with
short, dense hairs. Venation is prominent and
margins are rough. Auricles are absent or
rudimentary. The membranous ligule is very
short, about 1 mm, with fine hairs.

Foxtail

Hordeum jubatum

Juvenile

Foxtail barley is a fibrous-rooted, densely tufted perennial that spreads only by seed. The
stems are erect and smooth while the leaf sheaths are split and hairy. Foxtail barley tolerates
wet and moderately saline habitats.

Mature

The inflorescence is a dense, long-awned spike that may be greenish or purplish and nod to
one side. It has a jointed rachis that breaks into sharply pointed segments at maturity. Each
segment is made up of three spikelets, but only the central spikelet has one creamy-colored
seed. In addition, each segment has seven awns with upward-pointing barbs that easily
become attached to animals. If grazed, these barbed segments may become embedded in
the animal’s mouth and face, causing severe irritation, abscesses and even blindness.

% of fields
where found
0

Hi 5-15
Hi 16-50

50-1-

r not
surveyed

Key features

Greyish-green, slender leaves; tufted growth; barley-like, densely-awned heads

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat I

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

212

213

Green Foxtail

Setaria viridis

Other names

Wild millet, millet

Family

Grass Poaceae

Seedling

The first tiny leaf of green foxtail emerges
parallel to the ground. The leaf shape is
linear to lanceolate with a pointy tip. The
light green leaves are smooth and finely
veined, with a distinct lower midrib. Margins and
upper surface of leaf blades may feel slightly rough to
the touch. The ligule is a distinct fringe of hair which is an
excellent identification feature. Auricles are lacking and the margins of
the split sheath are trimmed with hair.

Juvenile

Green foxtail has a fibrous root system and often occurs in dense populations. The leaf
characteristics are especially useful to differentiate green from yellow foxtail. Yellow foxtail
lacks hairy sheath margins. Also, yellow foxtail has long, kinky hairs on the upper surface of
the leaves near the base of the blade. These hairs are completely lacking in green foxtail.

Mature

The soft, bristly spike-like panicle is green or purple-tinged and resembles a bottle brush.

It has densely packed spikelets with groups of bristles attached below the spikelets. Each
spikelet will produce only one seed, which is flattened on one side. The shiny seed is cream-
colored to brown to black, mottled and has a hard, wrinkly surface. The seeds of green
foxtail are smaller than those of yellow foxtail.

% of fields
where found
:5:ji 0
wem 14
■1 5-15
■1 16-50
50-1-
not

surveyed

Key features

Ligule a fringe of hair; sheath margins trimmed with hair; bristly spike-like panicle that
resembles a bottle brush

Similar species

Yellow foxtail Setaria glauca

Life Cycle

annual

winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage f

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas _/^

214

Key feature; bristly, spike-like panicle

Juvenile

Mature

215

Kochia

Kochia scoparia

Family

Goosefoot Chenopodiaceae

Seedling

Cotyledons are short and narrow. They are
often, but not always, bright pink to magenta
underneath. True leaves are sessile and linear
with a pointed tip. They have entire margins and
soft, long hairs on the surface. Many young leaves
emerge almost simultaneously to form a rosette. When the stem
elongates soon after, the leaves are alternately arranged on the stem.

Juvenile

Kochia has an erect, much-branched stem that is often purple-striped. The leaves of kochia
are densely hairy and have a greyish-green appearance. Main stem leaves are larger than
those on the lateral branches, which in turn have leaves that become smaller towards the
branch tips.

Mature

Flowers of kochia lack petals, but have five winged sepals. They are green and
inconspicuous in the leaf axils, often surrounded by clusters of long hairs. Each flower
develops into a flattened, dull brown, egg-shaped seed with a broad groove on each side.
Occasionally, the whole plant may develop bright red to magenta coloration in the fall to
give a “burning bush” appearance.

% of fields
where found
0

■g 14
50-h

■V "M not

surveyed

Key features

Rosette appearance of the young plant; greyish-green leaves covered with dense, soft, long
hairs; purple-striped stem

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat .

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides <[/^

forage crops, hay fields <y(j^

turf

waste areas

216

217

Family

Goosefoot Chenopodiaceae

Seedling

Cotyledons are narrow, linear and often
pink or purplish underneath. The first
two true leaves appear opposite, but
subsequent leaves are alternate. The
greyish-green leaves are petioled and have
mealy, white particles mainly on the lower leaf
surfaces. Leaves are ovate to triangular with
irregularly lobed or toothed margins.

Juvenile

The erect stem is branched, usually red or purple striped and ridged lengthwise. The leaves
are variable in shape, and margins vary from toothed to lobed to. entire. Net-seeded lamb’s-
quarters, Chenopodium berlandieri, is also very common in the prairie provinces. Although
its leaves tend to be thicker, it is difficult to distinguish from lamb’s-quarters until maturity.

Mature

Flowers are green and inconspicuous with no petals and five sepals. They are found in
dense clusters at the tips of branches and crowded into leaf axils. Each flower develops into
a shiny, black seed that is circular, flattened and covered with a plain, papery envelope. The
envelope is etched with reticulate or netted markings in net-seeded lamb’s-quarters. Also,
the sepals of net-seeded lamb’s-quarters are prominently keeled and do not completely
cover the fruit at maturity. The sepals of lamb’s-quarters are unkeeled and completely cover
the mature fruit.

% of fields
where found
0
1

H 16-50
50-H
not

surveyed

Key features

White, mealy particles on leaf undersurfaces; red or purple stripes on stems; dense clusters
of tiny, greyish-green flowers

Similar species

Net-seeded lamb’s-quarters Chenopodium berlandieri

Life Cycle

annual winter annual

biennial creeping perennial simple perennial

Habitat

conventional tillage <y<y^

rangeland

wetland

reduced tillage

irrigation

roadsides 4/^

forage crops, hay fields

turf

waste areas 4/^

218

Juvenile

Mature

219

Persian Darnel

Lolium persicum

Family

Grass Poaceae

Seedling

The young plant has very narrow leaf blades
that are shiny or glossy. Auricles are absent
on the first few seedling leaves. The ligule is
membranous, short and ragged. Leaf blade margins
and surfaces may be slightly rough to the touch.

Juvenile

Persian darnel is an erect, tufted annual with fibrous roots. The leaf sheath is split, smooth-
textured and has prominent veins. The leaves usually have small, claw-like auricles on the
middle and upper leaves of the plant.

Mature

The spike is composed of spikelets that are arranged edgewise to the rachis, making the
inflorescence appear flat. There is only one outer glume on each spikelet except for the
terminal spikelet, which has two glumes. Each spikelet is multi-floreted, and each floret
produces a thin, light brown seed with a slender, wispy awn at the tip.

Key features

Shiny leaf blade; spikelets edgewise to the rachis; one glume per spikelet; terminal spikelet
two-glumed

% of fields
where found
0

■I 16-BO
50 -F-
not

surveyed

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland ^

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas ^

220

221

Proso Millet

Panicum miliaceum

Other names

Broomcorn millet

Family

Grass Poaceae

Seedling

Proso millet seedlings resemble volunteer corn except that the leaves are narrower and
covered with dense, stiff hairs. No auricles are present. The ligule is membranous at the
base and fringed with hair along the top.

Juvenile

Proso millet is a plant that has escaped from cultivation. The plant is tufted with a fibrous
root system. Stems are erect or partially reclining with erect tips. Witch grass is a related
species, also densely hairy with the hairs bristling out at 90 degrees from the leaf blades and
sheaths. The sheaths of witch grass leaves are often purplish, and the plant is much shorter
in height than proso millet.

Mature

Proso millet is more easily distinguished from witch grass once it has headed out. The
panicle of proso millet is compact and usually erect to drooping. Witch grass is an airy,
delicate, loose panicle that may be up to half the height of the adult plant. Stems of witch
grass break off below the head, and the panicle tumbles along the ground dropping seed.
Proso millet panicles do not break off and are much coarser in appearance. The spikelets
of proso millet are about twice the size of witch grass ones, although both produce only a
single seed. Proso millet seeds are smooth and shiny, and they vary in color from yellow to
olive to black.

Key leatures

Dense hairiness of leaves; erect to partially reclining growth habit; erect to drooping panicle
with single-seeded spikelets

Similar species

Witch grass Panicum capillare

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

222

Panicle

Juvenile

Mature

223

Prostrate

Amaranthus blitoides

Family

Amaranth Amaranthaceae

Seedling

Prostrate pigweed has narrow, linear
cotyledons. The true leaves are alternate,
petioled and are wider at the tip than at
the base. There is a small indent at the
leaf tip with a soft spine in the centre.

The leaves have prominent white veins
underneath. Prostrate pigweed cotyledons are
longer in relation to the length of the first true
leaves than are cotyledons of redroot pigweed at the
same growth stage.

Juvenile

Prostrate pigweed forms prostrate, branching mats on the soil surface. Stems are fleshy and
often reddish. Tumble pigweed, a related species, has similar leaves and prominent white
venation but is erect with whitish-green stems. Other flat-growing species can be quite
easily distinguished from prostrate pigweed. Purslane has fleshy leaves, lacking prominent
venation. Prostrate knotweed has papery ocreas at the stem nodes, and thyme-leaved spurge
has white latex in the stems.

Mature

Green, inconspicuous flowers are clustered in leaf axils. The flowers lack petals but have
sepals and extra bracts around each flower. Although tumble pigweed also has green flowers
in the leaf axils, the plant is obviously erect, so it is unlikely to be confused with prostrate
pigweed. Tumble pigweed also has spiny-tipped bracts under each flower that are twice as
long as the sepals. The sepals and extra bracts under each flower of prostrate pigweed are
the same length.

Key features

Prostrate, branching mats on soil surface; leaves with soft spine at the tip and prominent,
white veins underneath; inconspicuous, green flowers in leaf axils

Similar species

Tumble pigweed Amaranthus albus

1 Habitat

conventional tillage

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields c/^

turf

waste areas

Life Cycle

annual

winter annual
biennial

creeping perennial
simple perennial

224

Juvenile

225

Quack

Grass

Elytrigia repens

Other names

Couch grass, twitch grass

Family

Grass Poaceae

Seedling

The first true leaves have hairy sheaths.

Auricles are small and claw-like. The ligule is
membranous but very short. The leaf margins
and upper surface of the leaf blade are rough, and
there may be sparse hair on the upper surface of the
blade.

Juvenile

Quack grass is more frequently seen growing from a rhizome than as a young seedling.

The rhizomes allow swift, vegetative propagation in the field, provide carbohydrate
storage during the winter and make quack grass a difficult weed to control. The tough,
whitish rhizomes are sharply pointed at the growing tip. Buds occur at the nodes, and a
brown bract covers part of each internode. Buds grow into rhizome branches or above-
ground shoots. There is often a noticeable M-shaped constriction near the lecif tips. Later
leaves tend to be less hairy than earlier ones.

Mature

The broad surface of quack grass spikelets is against the rachis, making this spike easily
distinguishable from Persian darnel, which has spikelets edgewise to the rachis. Each
spikelet is multi-floreted with two glumes that may have short awns. The florets may also
have a short awn on the tip. The seed is narrow and straw-colored at maturity.

Key features

Small, claw-like auricles; hairy sheaths on lower leaves; white rhizomes with brown bracts

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage
reduced tillage
forage crops, hay fields

rangeland

irrigation

turf

wetland

roadsides 4/^/^
waste areas

226

Ill

Family

Amaranth Amamnthaceae

Seedling

Cotyledons are long and narrow, with
short stalks. The first true leaves are
ovate and shallowly notched at the tip.

Close examination will reveal that the leaf
mid-vein extends as a small bristle into the
middle of the notch. Both the cotyledons and
early true leaves are frequently reddish on the
undersides. The young developing stem and tap root
are also usually red.

Juvenile

Redroot pigweed has erect, simple-to-branched stems. The stems are usually hairy and
green near the top of the plant and more smooth and reddish at the base. The tap root is
often still pinkish-red at this stage. Leaves are alternate, long-petioled and somewhat
diamond-shaped. The leaf margins vary from entire to slightly wavy, and it may sometimes
be difficult to recognize the notch at the tip. The undersides of the leaves are sparsely hairy
with prominent, white veins. The protruding veins and notched tip on the leaves help to
distinguish redroot pigweed from lamb’s-quarters, a weed often mistaken for it.

Mature

Tiny, green flowers are located in coarse, bristly spikes clustered at the top of the plant.

A short, central spike is usually surrounded by several smaller, finger-like spikes pointing
outwards. Small spikes are also frequently found in the axils of leaves. Each flower lacks
petals but has three, spiny-tipped bracts below. The bracts are what give the inflorescence
such a bristly, spiny appearance and feel. Each flower produces a tiny black, very shiny seed
that is almost round with a narrow, flattened margin.

% of fields

where

1 found

1-4

■i

5-15

■1

16-50

50-1-

not

surveyed

Key features

Red tap root and stem base; ovate to diamond-shaped leaves with a notched tip and
prominent veins below; numerous, bristly spikes

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat

conventional tillage
reduced tillage
forage crops, hay fields

rangeland

irrigation

turf

wetland
roadsides
waste areas

228

FIOWGr bristly spikes

Juvenile

Infestation

229

Russian Thistle

Salsola pestifer

Family

Goosefoot Chenopodiaceae

Seedling

Cotyledons are slender, needle-like and
succulent. The first two true leaves appear
opposite, but subsequent leaves are alternate.

Russian thistle leaves are succulent with soft spines
on the tips. This feature distinguishes the plant from
corn spurry, which has needle-like leaves lacking the spiny tip.

Corn spurry leaves are also whorled. Seedlings of knawel have non-succulent,
whorled or opposite leaves with hairs on the stems and leaves. Russian thistle leaves and
stems lack hairs.

Juvenile

Russian thistle is erect and much-branched. It develops a bushy, spherical appearance as
it matures. The stems are often red or purple striped. Young leaves are longer and more
succulent than later leaves, which are wedge-shaped and tipped with a strong, sharp spine.

Mature

The small, inconspicuous green flowers are located in leaf axils. The flowers have no petals,
but there are five papery sepals and two spiny-tipped bracts under each flower. The mature,
round, bushy plant breaks off at ground level and rolls with the wind to drop its seed. The
sepals remain attached around each seed as it falls off the plant. The dull grey seeds have a
coiled embryo, which can be seen through an almost transparent seed coat.

% of fields
where found
0

sm 14

■1 5-15
50-t-

^ 7 not

surveyed

Key features

Young leaves succulent, needle-like with soft spiny tips; mature leaves short, wedge-shaped
with strong, sharp spines; red or purple striped stems

230

Juvenile

Mature

Flower: flowers in leaf axils

231

Spear-leaved Goosefoot

Monolepis nuttalliana

Family

Goosefoot Chenopodiaceae

Seedling

Cotyledons are linear with short stalks. The first true leaves usually have long petioles and
are narrowly oval with two small “bumps” near the base. These bumps soon develop into
triangular lobes, giving the leaves the appearance of a spearhead.

Juvenile

Spear-leaved goosefoot typically forms a basal rosette early in the spring. The spear-shaped
leaves are thick and almost fleshy. Frequently, there is a light, powdery coating on the leaf
undersides. The rosettes form low, spreading stems and branches that are smooth, succulent
and often reddish. Spear-leaved goosefoot is similar to oak-leaved goosefoot, another low,
spreading weed in this family. These two species can be easily distinguished by the leaves
which are regularly and shallowly toothed around the margins in oak-leaved goosefoot.
Although originally most common on saline soils, spear-leaved goosefoot is now widely
adapted to gardens and cultivated fields across the prairies.

Mature

Small, inconspicuous flowers are located in axillary clusters. The flowers lack petals and
instead have only one green, bract-like sepal. Each flower produces one tiny, flattened seed.

Key features

Spear-shaped leaves; fleshy texture of stems and leaves; low, spreading growth habit

Similar species

Oak-leaved goosefoot Chenopodium glaucum

Life Cycle

annual winter annual biennial creeping perennial simple perennial

1 Habitat I

conventional tillage

rangeland

wetland 4^^

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

232

233

Stinging Nettle

Urtica dioica

Other names

American stinging nettle

Family

Nettle Urticaceae

Seedling

The cotyledons are oval with a notched tip. First true leaves are opposite and hairy with
round-toothed margins. On the prairies, stinging nettle is usually found in moist, shady
woodlands where seedlings are unlikely to he noticed. It can also he found in a variety
of habitats including horticultural crops.

Juvenile

Stinging nettle has vigorous, spreading rhizomes and tall, erect, square-angled stems.

Stems are equipped with specialized projections called “stinging hairs” that produce
localized swelling, itchiness and numbness when touched. The leaves are opposite, ovate
to lanceolate and toothed on the margins. The leaf petioles are long on the lower part of
the plant, becoming shorter towards the top. Stinging hairs are also found on the lower
leaf surfaces. There are stipules at the stem nodes. Hemp-nettle is sometimes confused
with stinging nettle, but it lacks both stinging hairs and stipules.

Mature

The small, green flowers are in separate male and female clusters produced in the leaf axils.
The spike-like chains of male flowers tend to be longer than the female ones. Individual
flowers of hemp-nettle are much larger with a pink to purple corolla. The pollen of stinging
nettle is one cause of summer hay fever. Seeds are tan to brown and egg-shaped.

Key features

Rhizomes; tall, square-angled stems with opposite leaves; flowers in spike-like chains in leaf
axils; stinging hairs

1 Life Cycle I

annual

winter annual

biennial

creeping perennial simple perennial

1 Habitat I

conventional tillage
reduced tillage
forage crops, hay fields

rangeland

irrigation

turf

wetland
roadsides
waste areas

234

Juvenile

235

Family

Buclovheat Polygonaceae

Seedling

Cotyledons are almost round with rounded
basal lobes and long stalks. Seedlings with
attached cotyledons are easy to distinguish
from wild buclcwheat seedlings, which have linear
cotyledons. The true leaves of tartary buckwheat are
broadly triangular with wide-spreading basal lobes.

Tartary Buckwheat

Fagopyrum tataricum

Juvenile

Tartary buclcwheat is tap-rooted with erect green stems and ocreas at the stem nodes.
Wild buclcwheat is readily distinguished from tartary buclcwheat by its weak, twining
stems. Leaves of tartary buclcwheat are alternate with long petioles on lower leaves and
short petioles on upper leaves. The triangular leaves are often wider than they are long.

Mature

Flowers are green and inconspicuous in leaf axils and at the tips of stems. There are no
petals, and the five sepals are unequal in length. The one seed that develops from each
flower protrudes from the sepals. The seed is brown or dark grey, three-sided and rough
on the edges. Each seed of wild buclcwheat is securely held by the sepals and is smaller
than that of tartary buclcwheat.

Key features

Broad, triangular leaves; erect stems with ocreas at the stem nodes; seed protruding from
the sepals

% of fields

where

\ found

5-15

16-50

50-1-

■ ' 'M

not

surveyed

Life Cycle

annual winter annual

biennial

creeping perennial simple perennial

Habitat

conventional tillage <y^

rangeland

wetland

reduced tillage

irrigation

roadsides

forage crops, hay fields

turf

waste areas

236

Seedlini

237

Thyme-leaved Spurge

Euphorbia serpyllifolia

Family

Spurge Euphorbiaceae

Seedling

Cotyledons of thyme-leaved spurge
are ovate. The true leaves are also ovate,
oppositely arranged and have finely toothed
margins.

Juvenile

Thyme-leaved spurge forms prostrate mats on the soil surface. All parts of the
plant are filled with a white, milky juice. This feature can be used to distinguish it from
other mat-forming species such as prostrate knotweed, prostrate pigweed and purslane,
which do not contain white latex. In addition, the leaves are opposite and finely toothed
in contrast to the others, which have alternate leaves and entire leaf margins.

Mature

The flowers are small and resemble those of leafy spurge. The separate female flower forms
a three-celled capsule with one seed in each compartment. The seeds are pitted and faintly
ridged.

Key features

Prostrate mats; milky juice in stems and leaves; opposite, finely toothed leaves

% of fields
where found

5-15

■■

16-50

50-1-

not

surveyed

annual

winter annual

Life Cycle

biennial creeping perennial simple perennial

conventional tillage ^

rangeland

wetland

reduced tillage ,/^j^

irrigation

roadsides

forage crops, hay fields

turf

waste areas

238

Juvenile

239

Wheat

Triticum aestivum

Other names

Hard red spring wheat, bread wheat

Family

Grass Poaceae

Seedling

The leaf blade and sheath are hairless to the naked eye. The leaves are narrower than those
of barley. The ligule is white, membranous and shorter than barley. Most characteristic are
the small, claw-like auricles trimmed with hair. Durum wheat auricles are hairless.

Juvenile

Wheat is a tufted plant with fibrous roots. Volunteer wheat can also be a weed and will
compete with the new crop.

The inflorescence is a spike with multi-floreted spikelets at the rachis nodes. The glumes are
quite large and have characteristic shapes depending on the variety. The florets have beards
or short awns extending from the tip of the floret. In contrast, durum wheat is typically
bearded. The hull is removed during combining, and the grain is a reddish brown, oval to
ovate to elliptical in shape. Durum grains are amber-colored, elliptical and larger than bread
wheat kernels.

Hair on the margins of the auricles; leaf blades narrower than barley; spike with a single,
multi-floreted spikelet at each rachis node

Mature

Key features

Similar species

Durum wheat Triticum durum

annual winter annual biennial creeping perennial simple perennial

conventional tillage

rangeland

wetland

roadsides

forage crops, hay fields

turf

waste areas

Juvenile

Mature

241

Wild Oats

Avena fatua

Family

Grass Poaceae

Seedling

Unlike most grasses, the seedling leaves
of wild oats twist counter-clockwise. A
tall, membranous ligule is easily visible at
the collar region by the three to four leaf
stage. Young plants may also be uprooted
and checked for the easy-to-recognize seed,
which is usually retained by the roots until
later stages of growth.

Juvenile

Wild oats produces stems that are erect, smooth and hollow. Leaf
blades are flat, broad and taper to a long thin point. They typically have a pronounced,
light-colored midrib. Leaf sheaths are split and overlapping. Sparse hair is often present on
both the blade and sheath in the collar region. Wild oats is very difficult to distinguish from
cultivated oats at the juvenile stage.

Mature

The inflorescence of wild oats is a large, widely-branched panicle, often seen waving above
the crop canopy. Each spikelet is usually comprised of two to three seeds surrounded by
two large, papery glumes. The glumes remain attached to the panicle after the seeds have
been dispersed. The seeds may vary greatly in color, from beige to brown to grey or black.
They are usually hairy, especially around the base, but can be smooth. Despite these
variations, all wild oat seeds are characterized by a large basal scar or “sucker mouth” and
a prominent, bent, twisted awn. Seeds of tame oats usually are beige, smooth and lack the
sucker mouth and long bent awn.

% of fields
where found

■cS

Ai'i

■i

5-15

16-50

50-h

■Hi

not

surveyed

Key features

Leaves with counter-cloclcwise twist and tall, membranous ligule; large, widely-branched
panicle inflorescence; seeds with sucker mouth and bent, twisted awn

Similar species

Oats Avena sativa

242

243

Glossary

Alternate - A leaf arrangement with one leaf
per stem node.

Annual - A species that germinates in the
spring, sets seed in the same year and then
dies.

Aquatic - Growing in water.

Auricles - Claw-like, paired structures found
at the collar in some grasses.

Awn - An extension at the tip of a floret or a
glume in some grasses.

Axillary - Arising in a leaf axil.

Axil - see “Leaf Axil”

Axis - The central line of a plant or plant
part.

Barb - A short, rigid bristle, often bent
baclcwards.

Basal - At the base of a plant or plant
structure. Often refers to the leaf
arrangement of a rosette.

Beak - A prolonged tip.

Beard - A long awn.

Biennial - A species that germinates in the
spring of the first year, producing a rosette
that survives the winter in a dormant state. It
resumes growth in the second year, flowers,
sets seed and then dies.

Blade - The expanded, flat portion of a leaf
above the sheath in grasses or above the
petiole in broadleaf plants.

Bract - A modified leaf, reduced in size.

Bud - A dormant or unopened leaf, branch or
flower, usually enclosed by protective bracts.

Bulb - An underground propagative structure
consisting of fleshy bracts attached to a
compressed stem.

Calyx - The collective term for the sepals of a
flower.

Capsule - A type of fruit with inner
compartments containing several to many
seeds.

Clasping - Referring to the base of leaves,
partially or entirely surrounding the stem.

Collar - Leaf tissue at the junction of the
blade and sheath in grasses.

Compound Leaf - A leaf with a blade
composed of two or more leaflets.

Compound Palmate Leaf - A compound leaf
with leaflets radiating from a common point.

Compound Pinnate Leaf - A compound leaf
with leaflets arranged on both sides of a
central axis (rachis). Same as pinnately
compound.

Compound Umbel - An inflorescence made
up of many small umbels at the top of the
main umbel.

Corolla - The collective term for the petals of
a flower.

Corona - A structure between the stamens
and the corolla in a Millcweed family flower.

Cotyledon - An embryonic leaf of a seed or
seedling. The shape, texture and attachment
of the two above-ground cotyledons of
broadleaf weed seedlings are useful
identification features.

245

Creeping Perennial - A species that survives
for three or more seasons and, in that way, is
similar to a simple perennial. However, a
creeping perennial has a specialized method
of vegetative propagation (rhizomes, stolons,
budding rootstocks) in addition to seed
production.

Crown - Shortened base of a stem below
ground level.

Dicotyledon - A broad classification of
flowering plants that are characterized by
having two cotyledons in the seed, broad
leaves with netted venation, flower parts in
four’s and fives’s and usually a taproot.

Disk Flower - Small, tube-like flower or
floret found in the Sunflower family.

Divided - Refers to a leaf margin that is cut
almost to the midrib.

Dormancy - A suspended or inhibited state
of growth.

Elliptical - Elongated oval in shape.

Embryo - The rudimentary plant contained
within the seed.

Endosperm - A food storage area in some
seeds.

Entire - Refers to a leaf margin with no teeth
or lobes.

Erect Stem - An upright or vertical stem.

Family - A grouping used in plant
classification consisting of a number of
similar genera.

Fibrous Root - A threadlike root. A plant
with a fibrous root system does not have a
main root.

Finely Divided - Refers to a leaf margin that
is deeply cut into many slender segments,
giving a lacy appearance.

Floral - Referring to a flower.

Floret - A small flower in the Grass or
Sunflower family.

Flower Head - A type of inflorescence with
many sessile flowers on a common, enlarged
receptacle found in the Sunflower family.

Also called a capitulum.

Flower Stalk - The stalk of a single flower,
also called a pedicel.

Fruit - The mature, seed-containing structure
that develops from a plant ovary.

Genus - A sub-division of a plant family. It
consists of a number of similar plant species.
(Plural of genus = genera)

Glabrous - Not hairy.

Glumes - A pair of bracts found at the base
of a spikelet in grasses.

Heading - Stage of growth when the
inflorescence is visibly emerging.

Hull - The collective term for the outer
coverings of a grass family floret.

Inflorescence - Floral arrangement of a plant.

Internode - The part of a plant stem between
two successive nodes.

Involucral Bract - A bract below the flower
head in the Sunflower family.

Involucre - One or several whorls of bracts
below a flower head in the Sunflower family.

246

Keel - Two united petals that form a pocket
in a Pea family flower.

Node - Place on the stem from where leaves
grow. Nodes are separated by internodes.

Keeled - Ridged, similar to the bottom of a
boat.

Ocrea - A sheath surrounding a stem node in
the Buclcwheat family.

Lanceolate - Shaped like the tip of a lance,
broadest near the base and tapering to the tip.

Opposite - A leaf arrangement with two
leaves per stem node, a paired leaf
arrangement.

Lateral - At or from the side.

Latex - White, milky juice in some plants.

Oval - Widest at the centre, narrowing to
both ends.

Leaf Axil - The upper angle that a leaf makes
with the stem to which it is attached.

Ovary - A part of the pistil that contains the
ovule (s), which ripen into seed(s).

Leaflet - One section of a compound leaf.

Ovate - Egg-shaped.

Ligule - A membranous or hairy projection at
the junction of the leaf blade and leaf sheath
in many grasses.

Ovule - A part of the ovary that develops into
a seed.

Palmate - Radiating pattern. A pattern of

Linear - Long and narrow with almost
parallel margins.

veins from a common point (as in a simple
palmate leaf) or a pattern of leaflets radiating
from a common point (as in a compound

Lobed - Refers to an undulating leaf margin.
Lobing varies from shallow to deep.

palmate leaf).

Panicle - A branched inflorescence in which

Margin - The edge of a leaf or other plant
part.

the flowers or spikelets are attached by flower
stalks to branches of the rachis.

Mealy - Granular texture.

Pappus - A calyx modified to form a tuft of
bristles or hairs on a seed. The pappus is an

Membranous - Similar to tissue paper or thin
skin.

adaptation to facilitate wind distribution of
seed.

Midrib - The central vein of a leaf or other
plant structure.

Petal - One of the parts of the corolla, often
coloured.

Monocotyledon - A broad classification of
flowering plants characterized by having one
cotyledon in the seed, narrow leaves with
parallel venation, flower parts in three’s and
six’s and a fibrous root system.

Petiole - A leaf stalk.

Pinnate - Feather-like pattern. A pattern of
veins emerging from both sides of a central
vein (as in a simple pinnate leaf) or a pattern
of leaflets arranged on both sides of a central
axis (as in a compound pinnate leaf) .

247

Pinnatifid - Divided in a pinnate pattern, but
not to the central vein.

Pistil - The female part of a flower consisting
of ovary, style and stigma.

Pod (Seedpod) - A type of fruit with many
seeds.

Prickle - A weak, spiny outgrowth.

Prostrate Stem - A horizontal stem which
grows flat or low to the ground.

Pubescent - Covered with hairs.

Raceme - A type of inflorescence in which
the flowers or spikelets have stalks and are
attached to a central rachis.

Rachis - The central axis of an inflorescence
or a compound leaf.

Ray Flower - A flower or floret with a flat,
strap-shaped petal, found in the Sunflower
family.

Receptacle - The enlarged end of a flower
stalk that holds the floral parts. In the
Sunflower family, many flowers are attached
to a greatly enlarged receptacle.

Reticulate - Referring to netted or non-
parallel venation on a leaf or other plant part.

Rhizome - A horizontal, underground stem
with buds and roots at the nodes.

Rib - A prominent vein or nerve.

Rosette - A cluster of radiating leaves at
ground level.

Scale - A leaf or bract greatly reduced in size.

Scalloped - Refers to shallow, rounded lobes
on a leaf margin.

Seed - A seed is the basic unit of plant
propagation. It is a ripened ovule containing
the embryo and surrounded by an outer coat.
Endosperm may or may not be present.

Seedling - A young plant that has grown
from a seed.

Sepal - One of the individual parts of the
calyx.

Septum - A partition or wall, usually inside a
fruit.

Sessile - Without a stalk.

Sheath - The lower, tubular portion of a grass
leaf enclosing the stem.

Simple Leaf - A leaf with a single,
unsegmented blade.

Simple Palmate Leaf - A simple leaf with
veins radiating from a common point.

Simple Perennial - A plant species that
survives for three or more seasons. Each
spring the plant regrows from stored root and
crown reserves. Seed production may occur
in the first season and in each subsequent
year. Spread of a simple perennial weed
species is primarily by seed.

Simple Pinnate Leaf - A simple leaf with a
central vein and smaller offshoots, similar to
a feather.

Species - The basic unit of plant
classification. Each weed in this book is a
separate plant species.

248

Spike - An inflorescence in which sessile
spikelets or flowers are attached to a central
rachis.

Spikelet - A unit of the inflorescence in
grasses, usually consisting of two outer
glumes and one or more florets.

Spine - A sharp, rigid projection.

Stamen - The male, pollen-producing part of
a flower.

Standard - The large, upper petal of a Pea
family flower.

Star-shaped Hairs - Branched hairs that
resemble a star.

Stem - The main supporting axis of a plant,
divided into nodes and internodes.

Stigma - The top of a pistil, which is adapted
(sticky, feathery) to receive pollen.

Stipules - Paired, leaf-like structures at a
stem node.

Stolon - A creeping, above-ground,
horizontal stem that roots at the nodes.

Style - Portion of a pistil between the ovary
and the stigma.

Succulent - Fleshy.

Taproot - A thickened, vertical root.

Terminal - At the end of a stem or branch.

Terrestrial - Growing on land.

Toothed - A general term to describe a saw-
like margin of a leaf or other structure.

Trifoliolate Leaf - A compound leaf with
three leaflets.

Tuber - Enlarged portion of a stem or root.

Tubercle - A small, rounded projection,
usually on a fruit or seed.

Tufted - In a clump.

Twining Stem - A weak stem that wraps
around other plants or objects for support.

Umbel - A flat-topped inflorescence with the
flower stalks radiating from a common point.

Valve - One section of the wall of a seedpod
or seed capsule.

Veins - The visible transporting tissue of a
leaf or other plant structure.

Venation - The pattern of veins on a leaf or
other plant structure.

Whorl - A generic term for three or more
plant structures arising from a common point.

Whorled - A type of leaf arrangement with
three or more leaves per stem node.

Wing - A thin, flattened extension of a seed,
fruit or other plant structure.

Wing Petal - One of the two lateral petals of
a Pea family flower.

Winter Annual - A species that germinates in
the fall and survives the winter as a dormant
rosette. It resumes growth in the spring, sets
seed in early summer and then dies.

249

Index

Organized by Common Name

Common name

absinth

American dragonhead
American stinging nettle

Scientific name

Artemisia absinthium
, Dracocephalum parviflomm

Family name

Sunflower

Mint

Asteraceae
• Lamiaccae

see stinging nettle

annual sow-thistle

similar to spiny annual sow-thistle

124

234

174

annual sunflower

similar to prairie sunflower

1^166 .

Argentine canola

Brassica napus

Mustard

Brassicaceae

126

baby’s-breath

Gypsophila paniculata

Pink

Caryophyllaceae

ball mustard

Neslia paniculata

Mustard

Brassicaceae

128

barley

Hordeum vulgare

Grass

Poaceae

196

barnyard grass

Echinochloa crusgalli

Grass

Poaceae

198

bedstraw

see cleavers

biennial wormwood

similar to absinth |

L J

■■ \ 1

[ 124

black henbane

Hyoscyamus niger

Nightshade

Solanaceae

130

black medick

Medicago lupulina

Pea

Fabaceae

132

black nightshade

similar to hairy nightshade

p-90 „

bladder campion

Silene cucubalus

Pink

Caryophyllaceae

blue buttons

see field scabious |

blue devil

see blueweed

blue lettuce i

similar to prickly lettuce

: ft

bluebur

Lappula squarrosa

Borage

Boraginaceae

blueweed

Echium vulgare

Borage

Boraginaceae

bread wheat

see wheat

240

broad-leaved plantain

Plantago major

Plantain

Plantaginaceae

200

broomcorn millet

see proso millet

222

buffalo-bean

see golden-bean

148

bull thistle

I Cirmm vulgare ' ' ■ ~ ' ~ j

Sunfh^er

burweed

see false ragweed

206

butter-and-eggs

see yellow toadflax

192

251

Organized by Common Name

Common name Scientific name

Family name Page

Canada fleabane
Canada thistle
cheat grass
cheeseweed
chickweed
cleavers
cocklebur
common burdock
common groundsel
common mullein
common pepper-grass
common tansy
compass plant
corn spurry
couch grass
cow cockle
creeping bellflower
creeping Charlie
creeping thistle
cupped nightshade
curlycup gumweed
cutleaf nightshade

Dalmatian toadflax

Erigeron canadensis
Cirsium arvense
see downy hrome
see round-leaved mallow
Stellaria media
Galium aparine
Xanthium strumarium

j Arctium minus
Senecio vulgaris

Verbascum thapsus
Lepidium densiflorum
see tansy
see prickly lettuce
Spergula arvensis
see quack grass
Vaccaria pyramidata
Campanula rdpunculbides
see ground-ivy

see Canada thistle
see hairy nightshade
see gumweed
see wild tomato

similar to yeUow toadflax

Sunflower

Asteraceae

Pink Caryophyllaceae

Madder Rubiaceae

Sunflower Asteraceae

Snapdragon Scrophulariaceae

Mustard Brassicaceae

Pink

Bluebell

Caryophyllaceae

Campanulaceae

204

100

202

134

136

178

168

226

150

120

dandelion

Taraxacum officinale

Sunflower

Asteraceae

138

death camas

Zygadenus gramineus

LUy

Liliaceae

devil’s paint-brush

see orange hawkweed

156

diffuse knapweed

Centaurea diffusa

Sunflower

Asteraceae

: dog mustard

Erucastrum gallicum

Mustard

Brassicaceae

140

252

Organized by Common Name ,

Common name Scientific name Family name Page

253

Organized by Common Name

Common name

Scientific name

Family name

Page

ground-ivy

Glechoma hederacea

Mint

Lamiaceae

gumweed

Grindelia squarrosa

Sunflower

Asteraceae

150

hairy nightshade

Solarium sarrachoides

Nightshade

Solanaceae

hard red spring wheat

see wheat

240

hemp-nettle

Galeopsis tetrahit

Lamium amplexicaule >

f Mint 1

Lamiaceae

henbit

Mint 1

Lamiaceae ^

hitch-hiker

see bluebur

horseweed

see Canada fleabane

hound’s-tongue \

1 Cynoglossum officinale |

j , .. ,

Borage ^ |

1 ■ ■ ■ ■ !

1 Boraginaceae

■ £

Johnny-go-to-bed-at-noon

fe... ......... - ■■ .. ,22®

see goat’s beard

146

knotgrass

knotweed^TS||||^
lady’s-thumb :

see prostrate knotweed ■

see prostrate knotweed a :'ig
Kochia scoparia

similar to pale smartweed ' .

Goosefoot

Chenopodiaceae

60
60
216
' 56

lamb’s-quarters

Chenopodium album

Goosefoot

Chenopodiaceae

218

leafy spurge

Euphorbia esula

Spurge

Euphorbiaceae

152

low larkspur

similar to tall larkspur C--

'My ■

'f-r ^ :• t . #■'

mare’s tail

see field horsetail

210

marsh elder

see false ragweed

206

millet

see green foxtail

214

mouse-eared chickweed

similar to chickweed

■

musk thistle

see nodding thistle

narrow-leaved hawk’s-beard

Crepis tectorum

Sunflower

Asteraceae

154

narrow-leaved milk-vetch

Astragalus pectinatus

Pea

Fabaceae

net-seeded lamb’s quarters

similar to lamb's-quarters

218

night-flowering catchfly

Silene noctiflora

Pink

Caryophyllaceae

nodding thistle

Carduus nutans I

Sunflower ^Jj||

^^teraceae

oak-leaved goc

.to spear-leaved goosefoot

254

Organized by Common Name

Common name

Scientific name

Family name

Page

oats ^

similar to wild oats *

; 242 ■

orange hawkweed

Hieracium aurantiacum

Sunflower

Asteraceae

156

ox-eye daisy

Chrysanthemum leucanthemum

Sunflower

Asteraceae

pale smartweed

Polygonum lapathifolium

Buckwheat

Polygonaceae

pasture sage

Artemisia frigida

Sunflower

Asteraceae

158

penny cress

see stinkweed

108

pepperweed

see common pepper-grass

perennial sow-thistle

Sonchus arvensis

Sunflower

Asteraceae

160

perennial sow-thistle

similar to arvensis

160

Persian darnel

Lolium persicum

Grass

Poaceae

220

pineappleweed

Matricaria matricarioides

Sunflower

Asteraceae

162

pinegrass

see field horsetail

210

Polish canola

Brassica rapa

Mustard

Brassicaceae

164

prairie onion |

similar to death camas

I 1

1 _

; 84

prairie rose J

similar to prickly rose

L H

L - J

^ 58

prairie sunflower

Helianthus petiolaris

Sunflower

Asteraceae

166

prickly annual sow-thistle

see spiny annual sow-thistle

174

prickly lettuce

Lactuca scariola

Sunflower

Asteraceae

168

prickly rose

Rosa acicularis

Rose

Rosaceae

proso millet

Panicum miliaceum

Grass

Poaceae

222

prostrate knotweed

Polygonum aviculare

" Buckwheat

Polygonaceae

prostrate pigweed

Amaranthus blitoides

Amaranth

Amaranthaceae

224

purple loosestrife

Lythrum salicaria ^

Loosestrife

; Lythraccae

purslane

Portulaca oleracea

Purslane

Portulacaceae

170

pygmyflower

Androsace septentrionalis

Primrose

Primulaceae

quack grass

Elytrigia repens

Grass

Poaceae

226 [

redroot pigweed

Amaranthus retroflexus

Amaranth

Amaranthaceae

228

redstem filaree

see stork’s-bill

255

Organized by Common Name

Common name

Scientific name

Family name

Page

rough cinquefoil

Potentilla norvegica

Rose

Rosaceae

172

round-leaved mallow

Malva rotundifolia

Mallow

Malvaceae

100

Russian knapweed

Centaurea repens

i Sunflower |

^^A^raceae

L 36

Russian thistle

Salsola pestifer

Goosefoot

Chenopodiaceae

230

scentless chamomile

Matricaria perforata

Sunflower

Asteraceae

102

scentless mayweed

see scentless chamomile

102

scouring rush

see field horsetail

210

shepherd’s purse

Capsella bursa-pastoris

Mustard

Brassicaceae

104

showy milkweed

Asclepias speciosa

Il'Milkweed ^ |

j Asclepiadaceae

silky lupine

Lupinus sericeus

Pea

Fabaceae

silvery lupine

smooth brome

similar to silky lupine

similar to downy brome

soapwort

spear-leaved goosefoot

spiny annual sow-thistle

spotted knapweed

spotted water-hemlock

stickseed

stickweed

sticky cockle

stinging nettle

stinking mayweed

stinkweed

stork’s-bill

striate knotweed

swamp smartweed

tall buttercup

tall larkspur

see cow cockle

Monolepis nutalliana
Sonchus asper

Centaurea maculosa
Cicuta maculata
see bluebur
see bluebur

see night -flowering catchfly
Urtica dioica

Goosefoot
Sunflower
J Sunflower
Parsley

Chenopodiaceae

Asteraceae

Apiaceae

similar to scentless chamomile
Thlaspi arvense
Erodium cicutarium
similar to pTpstmte-knpfweed
simMar to water smartweeUrW: -
Ranunculus acris
Delphinium glaucuni

Nettle

Mustard

Geranium

Urticaceae

Brassicaceae

Geraniaceae

204

232

174

106

234

108

Buttercup

: '.r '• -

Ranimculaceae

Ranunculaceae

256

Organized by Common Name

Common name

Scientific name

Family name

tansy

Tanacetum vulgare

Sunflower

Asteraceae

tansy mustard

see flixweed

tartary buckwheat

Fagopyrum tataricum

Buckwheat

Polygonaceae

thyme-leaved spurge

Euphorbia serpyllifolia

Spurge

Euphorbiaceae

tumble mustard
tumble pigweed
turnip rape

Sisymbrium altissimum Mustard

see Polish canola ^

Brassicaceae

twitch grass

see quack grass

two-grooved milk-vetch

Astragalus bisulcatus

Fabaceae

Viper’s bugloss

see blueweed

water smartweed i

Polygonum amphibium

, . / V * Buckwheat

■■ ■

. ■ Polygonaceae

water-parsnip

western dock j

similar to spotted water-hemloc^SB^^^^^B^M
similar to field dock

western salsify

see goat’s beard

wheat

Triticum aestivum

Grass

Poaceae

white camas

\ similar to death camas

1. 7

white clover

Trifolium repens

Pea

Fabaceae

white cockle

Silene alba

Pink

Caryophyllaceae

white daisy

see ox-eye daisy

white sweet clover

similar to yellow sweet clover

- . J

wild barley

see foxtail barley

wild buckwheat

Polygonum convolvulus

Buckwheat

Polygonaceae

wild caraway

Carum carvi

Parsley

Apiaceae

wild carrot

\ similar to wild caraway

wild chamomile

similar to scentless chamomile

wild licorice
wild millet
wild mustard

178

144

236

238

180

224

164

226

106

208

146

240

112

^90

212

114

116

|116

Glycynhiza lepidota
see green foxtail
Brassica kaber

Pea

Mustard

Fabaceae

Brassicaceae

118

214

182'

257

Organized by Common Name :/

Common name

Scientific name Family name Page

wild oats

Avenafatua Grass . Poaceae 242

wild portulaca
wild radish
wild rose
wild snapdragon
wild tomato

see purslane :

Raphanus raphanistmm Mustard Brassicaceae 184

see yellow toadflax 192

Solanum triflorum Nightshade Solanaceae 120

witch grass J

wood whitlow-grass

Draba nemorosa Mustard Brassicaceae 186

Woods’ rose 1

wormwood

^similar to prickly rose

see absinth 124

yellow foxtail ^ j

[ similar to green foxtail ' I 214

j yellow nutsedge Cyperus esculentus Sedge Cyperaceae 188

yellow star-thistle j

yellow star-thistle 1

yellow sweet clover

\ similar to spot^d knapweed^ ^ i -

1 similar to diffuse knapweed \ ^6

Melilotus officinalis Pea Fabaceae 190 ;

yellow toadflax

Linaria vulgaris Snapdragon Scrophulariaceae 192

yellow whitlow-grass

see wood whitlow-grass 186

yellow-flowered hemp-nettle”^

\ similar to hemp-nettle 52

258

Organized by Scientific

'Name

Scientific name

Common name

Family name

Page

Amaranthus blitoides

prostrate pigweed

Amaranth

224

Amaranthus retroflexus

redroot pigweed

Amaranth

228

Androsace septentrionalis

pygmyflower

Primrose

Arctium minus

common burdock

Sunflower

; 26

Artemisia absinthium

absinth

Sunflower

124

Artemisia frigida

pasture sage

Sunflower

158

Asclepias speciosa

showy milkweed

Milkweed

Astragalus bisulcatus I

j two-grooved milk-vetch

Pea

Astragalus pectinatus

narrow-leaved milk-vetch

Pea

Avena fatua

wild oats

Grass

242

Brassica kaber

wild mustard

Mustard

182

Brassica napus

Argentine canola

Mustard

126

Brassica rapa

Polish canola

Mustard

164

Bromus tectorum

downy brome

Grass

204

Campanula rapimculoides

j creeping bellflower

BluebeU

Capsella bursa-pastoris

shepherd’s purse

Mustard

104

Carduus nutans |

nodding thistle

Sunflower

Carum carvi

wild caraway

Parsley

116

Centaurea diffusa

diffuse knapweed

Sunflower

Centaurea maculosa

spotted knapweed

Sunflower

Centaurea repens

Russian knapweed

Sunflower

^ 36

Chenopodium album

lamb’s-quarters

Goosefoot

218

Chrysanthemum leucanthemum

ox-eye daisy

Sunflower

Cicuta maculata

spotted water-hemlock

Parsley

106

Cirsium arvense

1 Canada thistle

1 Sunflower ^

Cirsium vulgare

j bull thistle

Sunflower

;

Convolvulus arvensis

field bindweed

Morning-glory

Crepis tectorum

narrow-leaved hawk’s-beard

Sunflower

154

Organized by Scientific Name

Scientific name

Common name

Family name

Page

Cynoglossum officinale

hound’s-tongue

Borage

! 30 ,

Cyperus esculentus

yellow nut sedge

Sedge

188

Delphinium glaucum

tali larkspur

Buttercup

Descurainia sophia

flixweed

Mustard

144

Draba nemorosa

wood whitlow-grass

Mustard

186

Dracocephalum parviflorum

American dragonhead

Mint

Echinochloa crusgalli

barnyard grass

Grass

198

Echium vulgare

blueweed

Borage

Elytrigia repens

"quack grass

Grass

226

Equisetum arvense

m“"‘W

field horsetail

Horsetail

210

Eiigeron canadensis

Canada fleabane

Sunflower

Erodium cicutarium

[ stork’s-bill

1 Geranium

Emcastrum gallicum

dog mustard

Mustard

140

Euphorbia esula

leafy spurge

Spurge

152

Euphorbia serpyllifolia

thyme-leaved spurge

Spurge

238

Fagopyrum tataricum

tartary buckwheat

Buckwheat

236

Galeopsis tetrahit

hemp-nettle

Mint

Galium aparine

cleavers

Madder

Glechoma hederacea

ground-ivy

Mint

Glycyrrhiza lepidota

wild licorice

Pea

118

Grindelia squarrosa

gumweed

Sunflower

150

Gypsophila paniculata

baby’s-breath

Pink

Helianthus petiolaris

prairie sunflower

Sunflower

166

Hieracium aurantiacum

orange hawkweed

Sunflower

156

Hordeum jubatum

foxtail barley

Grass

212

Hordeum vulgare

barley

Grass

196

Hyoscyamus niger

black henbane

Nightshade

130

Iva xanthifolia

false ragweed

Sunflower

206

Organized by Scientific Name

Scientific name

Common name

Family name

Page

Knautia arvensis I

field scabious

Teasel

Kochia scoparia

kochia

Goosefoot

216

Lactuca scariola

prickly lettuce

Sunflower

168

Lamium amplexicaide

henbit

Mint

Lappula squarrosa

bluebur

Borage

Lepidium densiflorum

common pepper-grass

Mustard

Linaria vulgaris

yellow toadflax

Snapdragon

192

Linum usitatissimum

flax

Flax

Lolium persicum

Persian darnel

Grass

220

Lupinus sericeus

silky lupine

Pea

Lythrum salicaria

purple loosestrife

Loosestrife i

: 34

Malva rotundifolia

round-leaved mallow

Mallow

100

Matricaria matricarioides

pineappleweed

Sunflower

162

Matricaria perforata

scentless chamomile

Sunflower

102

Medicago lupulina

black medick

Pea

132

Melilotus officinalis

yellow sweet clover

Pea

190

Monolepis nutalliana

spear-leaved goosefoot

Goosefoot

232

Neslia paniculata

ball mustard

Mustard

128

Oxytropis sericea

early yellow locoweed

Pea

142

Panicum miliaceum

proso millet

Grass

222

Plantago major

broad-leaved plantain

Plantain

200

Polygonum amphibium

j water smartweed

Buckwheat

Polygonum aviculare

prostrate knotweed

Buckwheat

Polygonum convolvulus

wild buckwheat

Buckwheat

114

Polygonum lapathifolium

pale smartweed

Buckwheat

Portulaca oleracea

purslane

Purslane

170

Potentilla norvegica

rough cinquefoil

Rose

172

Ranunculus acris

tall buttercup

Buttercup

176

281

Organized by Scientific Name

Scientific name Common name Family name Page

Raphanus raphanistnim

wild radish

Mustard

184

Rosa acicularis

prickly rose

^ Rose

Rumex pseudonatronatus

field dock

Buckwheat

208

Salsola pestifer

Russian thistle

Goosefoot

230

Senecio vulgaris

common groundsel

Sunflower

134

Setaria viridis

green foxtail

Grass

214

Silene alba

white cockle

Pink

112

Silene cucubalus

bladder campion

Pink

Silene noctiflora

night-flowering catchfly

Pink

Sisymbrium altissimum

tumble mustard

Mustard

180

Solanum sarrachoides

hairy nightshade

Nightshade

Solanum triflorum

wild tomato

Nightshade

120

Sonchus arvensis

perennial sow-thistle

Sunflower

160

Sonchus asper

spiny annual sow-thistle

Sunflower

174

Spergula arvensis

corn spurry

Pink

Stellaria media

chickweed

Pink

Tanacetum vulgare

tansy

Sunflower

178

Taraxacum officinale

dandehon

Sunflower

138

Thermopsis rhombifolia

golden-bean

Pea

148

Thlaspi arvense

stinkweed

Mustard

108

Tragopogon dubius

goat’s-beard

Sunflower

146

Trifolium repens

white clover

Pea

Triticum aestivum

wheat

Grass

240

Urtica dioica

stinging nettle

Nettle

234

Vaccaria pyramidata

cow cockle

Pink

Verbascum thapsus

common mullein

Snapdragon

136

Xanthium strumarium

cocklebur

Sunflower

202

Zygadenus gramineus

death camas

Lily

262

^ ■ " “ _ , ' --y 1

Organized by Family Name

Family name

Common name

Scientific name

Page

Amaranth

Amaranthaceae

prostrate pigweed

Amaranthus blitoides

224

redroot pigweed

Amaranthus retroflexus

228

Bluebell

Campanulaceae

creeping bellflower

Campanula rapunculoides

Borage

Bomginaceae

bluebur

Lappula squarrosa

blueweed

Echium vulgare

hound’s-tongue

Cynoglossum officinale

Buckwheat

Pofygonaceae

field dock

Rumex pseudonatronatus

208

tartary buckwheat

Fagopyrum tataricum

236

pale smartweed

Polygonum lapathifolium

prostrate knotweed

Polygonum aviculare

water smartweed

Polygonum amphibium

wild buckwheat

Polygonum convolvulus

114

Buttercup

Ranunculaceae

tall larkspur

Delphinium glaucum

tall buttercup

Ranunculus acris

176

Flax

Linaceae

flax

Linum usitatissimum

Geranium

Geraniaceae

stork’s-biil

Erodium cicutarium

Goosefoot

Chenopodiaceae

kochia

Kochia scoparia

216

lamb’s-quarters

Chenopodium album

218

Russian thistle

Salsola pestifer

230

spear-leaved goosefoot

Monolepis nutalliana

232

Grass

Poaceae

barley

Hordeum vulgare

196

barnyard grass

Echinochloa crusgalli

198

downy brome

Bromus tectorum

204

foxtail barley

Hordeum jubatum

212

green foxtail

Setaria viridis

214

Persian darnel

Folium persicum

220

proso millet

Panicum miliaceum

222

quack grass

Elytrigia repens

226

263

Organized by Family Name

Family name Common name Scientific name

Grass

Poaceae

wheat

Triticum aestivum

wild oats

Avenafatua

Horsetail

Equisetaceae

field horsetail

Equisetum arvense

Lily

Liliaceae

death camas

Zygadenus gramineus

Loosestrife

Lythraceae

1 purple loosestrife

Lythrum salicaria -

Madder

Rubiaceae

cleavers

Galium aparine

Mallow

Malvaceae

round-leaved mallow

Malva rotundifolia

Milkweed

Asclepiadaceae

showy milkweed' "■*

1 Asclepias speciosa

Mint

Lamiaceae

ground-ivy

Glechoma hederacea

American dragonhead

^Nacocephalum parviflorum

1 hemp-nettle ■ '?■

\ ’ - ■ ■■ ■ ' . ■ ■ ;

1 Galeopsis tetrahit

i henbit

1 Lamium amplexicaule

Morning-glory

Convolvulaceae

field bindweed

Convolvulus arvensis

Mustard

Brassicaceae

common pepper-grass

Lepidium densiflorum

shepherd’s purse

Capsella bursa-pastoris

stinkweed

Thlaspi arvense

Argentine canola

Brassica napus

ball mustard

Neslia paniculata

dog mustard

Erucastrum gallicum

fUxweed

Descurainia sophia

Polish canola

Brassica rapa

tumble mustard

Sisymbrium altissimum

wild mustard

Brassica kaber

wild radish

Raphanus raphanistrum

wood whitlow-grass

Draba nemorosa

Nettle

Urticaceae

stinging nettle

Urtica dioica

Nightshade

Solanaceae

hairy nightshade

Solanum sarrachoides

wild tomato

Solanum triflorum

240

242

210

100

104

108

126

128

140

144

164

180

182

184

186

234

120

264

Organized by Family Name

Family name Common name Scientific name

Nightshade

Solanaceae

black henbane

Hyoscyamus niger

Parsley

Apiaceae

spotted water-hemlock

Cicuta maculata

wild caraway

Carum carvi

Pea

Fabaceae

silky lupine

Lupinus sericeus

two-grooved milk-vetch

Astragalus bisulcatus

narrow-leaved milk-vetch

Astragalus pectinatus

white clover

Trifolium repens

wild licorice

Glycyrrhiza lepidota

black medick

Medicago lupulina

early yellow locoweed

Oxytropis sericea

golden-bean

Thermopsis rhombifolia

yellow sweet clover

Melilotus officinalis

Pink

Caryophyllaceae

cow cockle

Vaccaria pyramidata

baby’s-breath

Gypsophila paniculata

bladder campion

Silene cucubalus

chickweed

Stellaria media

corn spurry

Spergula arvensis

night-flowering catchfly

Silene noctiflora

white cockle

Silene alba

Plantain

Plantaginaceae

broad-leaved plantain

Plantago major

Primrose

Primulaceae

pygmyflower

Androsace septentrionalis

Purslane

Portulacaceae

purslane

Portulaca oleracea

Rose

Rosaceae

prickly rose

Rosa acicularis

rough cinquefoil

Potentilla norvegica

Sedge

Cyperaceae

yellow nut sedge

Cyperus esculentus

Snapdragon

Scrophulariaceae

common mullein

Verbascum thapsus

yellow toadflax

Linaria vulgaris

Spurge

Euphorbiaceae

thyme-leaved spurge

Euphorbia serpyllifolia

130

106

116

118

132

142

148

190

112

200

170

172

188

136

192

238

265

Organized by Family Name

Family name Common name Scientific name Page

A ro .

7 78753"06147 9

AGRICULTURE, FOOD AND
RURAL DEVELOPMENT

AGDEX 640-4

^^7

.Jk,. OLDS
COLLEC

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